Frequency conversion control method and device for ship cooling system

Abstract

The embodiment of the invention discloses a frequency conversion control method and device for a ship cooling system, electronic equipment and a storage medium. According to the technical scheme provided by the embodiment of the invention, under the condition that the ship is in the navigation mode, the first fresh water temperature of the fresh water cooling subsystem corresponding to the main cooler and the second fresh water temperature of the fresh water cooling subsystem corresponding to the auxiliary cooler are collected, and the starting number and the operation rotating speed of the sea water pumps are controlled based on the first fresh water temperature; the opening degree of the control valve of the corresponding slave cooler is controlled based on the second fresh water temperature; and under the condition that the ship is in the berthing mode, the main cooler is closed, the third fresh water temperature of the fresh water cooling subsystem corresponding to the specified slave cooler is collected, the opening number and the operation rotating speed of the sea water pump are controlled based on the third fresh water temperature, and the control valve corresponding to the specified slave cooler is controlled to be the maximum opening degree. By adopting the technical means, accurate seawater flow distribution of multiple sets of fresh water cooling systems can be realized, so that energy waste is avoided.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of ship technology, and in particular to a frequency conversion control method, device, electronic equipment, and storage medium for a ship cooling system. Background Art

[0002] At present, during the operation of ships, their power units and other equipment generate a large amount of waste heat, which requires an efficient cooling system to dissipate heat to ensure the normal operating temperature of key equipment such as the main engine, auxiliary engines, and generators. The ship's cooling system usually adopts a central cooling form, consisting of a freshwater cooling system and a seawater system. Among them, the low-temperature fresh water flows through the equipment that needs to be cooled (such as the main engine cylinder jacket water, generator cooler, etc.) to absorb heat, and then enters the central cooler. In the central cooler, the heat is transferred to the low-temperature seawater, and finally the seawater carries the heat to the overboard. Generally speaking, the cooling water system uses a fixed-frequency pump (seawater pump, freshwater pump) to drive the cooling water circulation. Under this control method, the pump always runs at the rated speed to perform cooling operations.

[0003] However, for ship cooling systems that utilize multiple freshwater cooling systems, simply controlling the pump speed with a fixed frequency cannot precisely regulate the cooling water temperature, potentially leading to overcooling of the equipment at low loads or insufficient cooling during sudden load changes. Furthermore, equipment cooled by different freshwater systems requires different amounts of heat dissipation under different operating conditions. Continuously operating a fixed-frequency pump at full load in such situations could consume a significant amount of unnecessary electricity, resulting in significant energy waste. Summary of the Invention

[0004] The embodiments of the present application provide a frequency conversion control method, device, electronic equipment and storage medium for a ship cooling system, which can accurately control the frequency conversion of the seawater pump of the ship cooling system, realize accurate distribution of seawater flow in multiple sets of freshwater cooling systems, and solve the technical problem of inaccurate distribution of seawater flow in the ship cooling system.

[0005] In a first aspect, an embodiment of the present application provides a variable frequency control method for a ship cooling system, the ship cooling system comprising a variable frequency controller, a seawater subsystem, a plurality of fresh water cooling subsystems, and a corresponding plurality of central coolers, the seawater subsystem being connected to each of the central coolers via a seawater circulation pipeline, and each of the fresh water cooling subsystems being connected to a corresponding central cooler via a fresh water circulation pipeline, the central cooler being configured to perform heat exchange based on seawater in the seawater circulation pipeline and fresh water in the fresh water circulation pipeline to perform equipment cooling operations; the central cooler comprising a master cooler and a plurality of slave coolers, the seawater circulation pipeline being provided with a seawater pump and a control valve corresponding to each of the slave coolers, the seawater pump being configured to control a total water inlet flow rate of the seawater subsystem, the control valve being configured to control the water inlet flow rate of the corresponding slave cooler, the fresh water circulation pipeline corresponding to each of the fresh water cooling subsystems being provided with a temperature sensor for real-time detection of the fresh water temperature of the corresponding fresh water circulation pipeline, the variable frequency controller being signal-connected to the seawater pump, the control valve, and the temperature sensor, respectively; The frequency conversion control method of the ship cooling system includes: When the ship is in sailing mode, the frequency conversion controller collects a first fresh water temperature of the fresh water cooling subsystem corresponding to the main cooler and a second fresh water temperature of the fresh water cooling subsystem corresponding to the slave cooler, controls the number of seawater pumps to be opened and the operating speed based on the first fresh water temperature, and controls the opening of the control valve of the corresponding slave cooler based on the second fresh water temperature; When the ship is in mooring mode, the main cooler is turned off, and the third fresh water temperature of the fresh water cooling subsystem corresponding to the designated slave cooler is collected based on the frequency conversion controller. The number of openings and the operating speed of the seawater pump are controlled based on the third fresh water temperature, and the control valve corresponding to the designated slave cooler is controlled to be at the maximum opening.

[0006] Furthermore, the controlling the number of activations and the operating speed of the seawater pump based on the first fresh water temperature includes: In the case where a plurality of seawater pumps are turned on, if the designated seawater pump is running at the lowest speed and the first fresh water temperature is lower than a first set threshold, turning off the designated seawater pump; In the case of turning on one of the seawater pumps, if the first fresh water temperature is higher than a second set threshold, the number of the turned-on seawater pumps is increased.

[0007] Furthermore, increasing the number of times the seawater pump is turned on includes: According to the accumulated operating time of each of the currently unactivated seawater pumps, the seawater pump with the shortest accumulated operating time is selected for activation.

[0008] Furthermore, the controlling the number of activations and the operating speed of the seawater pump based on the third fresh water temperature includes: In the case where the plurality of seawater pumps are turned on, if the designated seawater pump is running at the lowest speed and the third fresh water temperature is lower than the first set threshold, turning off the designated seawater pump; In the case of turning on one of the seawater pumps, if the third fresh water temperature is higher than the second set threshold, the number of the turned-on seawater pumps is increased.

[0009] Furthermore, controlling the opening of the control valve of the corresponding slave cooler based on the second fresh water temperature includes: The opening of the control valve of the slave cooler is dynamically adjusted based on a PID algorithm to ensure that the second fresh water temperature is within a set temperature range.

[0010] Furthermore, the method further comprises: In the set operation mode, the seawater pump is controlled to operate at full load, and the control valve is set to the maximum opening.

[0011] Furthermore, the method further comprises: A ship operating condition signal is detected, and the navigation mode and the mooring mode are switched based on the ship operating condition signal.

[0012] In a second aspect, an embodiment of the present application provides a variable frequency control device for a ship cooling system, the ship cooling system comprising a variable frequency controller, a seawater subsystem, a plurality of fresh water cooling subsystems, and a corresponding plurality of central coolers, the seawater subsystem being connected to each of the central coolers via a seawater circulation pipeline, and each of the fresh water cooling subsystems being connected to a corresponding central cooler via a fresh water circulation pipeline, the central cooler being configured to perform heat exchange based on seawater in the seawater circulation pipeline and fresh water in the fresh water circulation pipeline to perform equipment cooling operations; the central cooler comprising a master cooler and a plurality of slave coolers, the seawater circulation pipeline being provided with a seawater pump and a control valve corresponding to each of the slave coolers, the seawater pump being configured to control a total water inlet flow of the seawater subsystem, the control valve being configured to control the water inlet flow of the corresponding slave cooler, the fresh water circulation pipeline corresponding to each of the fresh water cooling subsystems being provided with a temperature sensor for detecting the fresh water temperature of the corresponding fresh water circulation pipeline in real time, the variable frequency controller being signal-connected to the seawater pump, the control valve, and the temperature sensor, respectively; The frequency conversion control device of the ship cooling system includes: a navigation control module, configured to, when the ship is in navigation mode, collect, based on the frequency conversion controller, a first fresh water temperature of the fresh water cooling subsystem corresponding to the main cooler and a second fresh water temperature of the fresh water cooling subsystem corresponding to the slave cooler, control the number of seawater pumps to be opened and the operating speed based on the first fresh water temperature, and control the opening of the control valve of the corresponding slave cooler based on the second fresh water temperature; The mooring control module is used to, when the ship is in mooring mode, shut down the main cooler, collect the third fresh water temperature of the fresh water cooling subsystem corresponding to the designated slave cooler based on the frequency conversion controller, control the number of seawater pumps opened and the operating speed based on the third fresh water temperature, and control the control valve corresponding to the designated slave cooler to the maximum opening.

[0013] In a third aspect, an embodiment of the present application provides an electronic device, including: memory and one or more processors; The memory is used to store one or more programs; When the one or more programs are executed by the one or more processors, the one or more processors implement the frequency conversion control method for a ship cooling system as described in the first aspect.

[0014] In a fourth aspect, an embodiment of the present application provides a storage medium containing computer-executable instructions, which, when executed by a computer processor, are used to execute the variable frequency control method for a ship cooling system as described in the first aspect.

[0015] In the embodiment of the present application, when the ship is in navigation mode, the frequency conversion controller is used to collect the first fresh water temperature of the fresh water cooling subsystem corresponding to the main cooler and the second fresh water temperature of the fresh water cooling subsystem corresponding to the slave cooler, and the number of seawater pumps opened and the operating speed are controlled based on the first fresh water temperature, and the opening of the control valve of the corresponding slave cooler is controlled based on the second fresh water temperature; when the ship is in mooring mode, the main cooler is turned off, and the frequency conversion controller is used to collect the third fresh water temperature of the fresh water cooling subsystem corresponding to the designated slave cooler, and the number of seawater pumps opened and the operating speed are controlled based on the third fresh water temperature, and the control valve corresponding to the designated slave cooler is controlled to the maximum opening. By adopting the above technical means, the seawater pumps and coolers of the ship cooling system are precisely controlled by frequency conversion, and the seawater flow of multiple freshwater cooling systems is precisely distributed, thereby avoiding energy waste, improving the control accuracy of the ship cooling system, and improving the stability and reliability of the equipment cooling operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1This is a flow chart of a frequency conversion control method for a ship cooling system provided in Example 1 of the present application; Figure 2 This is a schematic structural diagram of a ship cooling system in Example 1 of the present application; Figure 3 This is a flow chart of seawater pump control based on the first fresh water temperature in Example 1 of the present application; Figure 4 This is a flow chart of seawater pump control based on the third fresh water temperature in Example 1 of the present application; Figure 5 This is a structural diagram of a frequency conversion control device for a ship cooling system provided in Example 2 of the present application; Figure 6 This is a structural diagram of an electronic device provided in Example 3 of the present application. DETAILED DESCRIPTION

[0017] To further clarify the objectives, technical solutions, and advantages of this application, specific embodiments of the present application are described in further detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are intended only to illustrate this application and are not intended to limit it. It should also be noted that, for ease of description, the drawings only illustrate portions relevant to this application, not all of them. Before discussing the exemplary embodiments in more detail, it should be noted that some exemplary embodiments are described as processes or methods depicted as flowcharts. Although the flowcharts depict the various operations (or steps) as sequential processes, many of the operations can be performed in parallel, concurrently, or simultaneously. Furthermore, the order of the operations can be rearranged. The process may terminate upon completion of its operations, but may also include additional steps not shown in the accompanying drawings. The process may correspond to a method, function, procedure, subroutine, subprogram, or the like.

[0018] Example 1: Figure 1 A flowchart of a frequency conversion control method for a ship cooling system provided in Example 1 of the present application is provided. The frequency conversion control method for a ship cooling system provided in this embodiment can be executed by a frequency conversion control device for the ship cooling system. The frequency conversion control device for the ship cooling system can be implemented via software and / or hardware. The frequency conversion control device for the ship cooling system can be composed of two or more physical entities, or a single physical entity. Generally speaking, the frequency conversion control device for the ship cooling system can be a control device such as a system controller or a frequency conversion controller for the ship cooling system.

[0019] The following description will be made by taking the frequency conversion controller of the ship cooling system as an example to implement the frequency conversion control method of the ship cooling system. Figure 1 The frequency conversion control method of the ship cooling system specifically includes: S110. When the ship is in navigation mode, the first fresh water temperature of the fresh water cooling subsystem corresponding to the main cooler and the second fresh water temperature of the fresh water cooling subsystem corresponding to the slave cooler are collected based on the frequency conversion controller, the number of seawater pumps opened and the operating speed are controlled based on the first fresh water temperature, and the opening of the control valve of the corresponding slave cooler is controlled based on the second fresh water temperature.

[0020] The frequency conversion control method of the ship cooling system of the present application is intended to perform frequency conversion control of the ship cooling system under different ship operation modes, thereby realizing accurate distribution of seawater flow to each fresh water cooling system. Figure 2 The ship cooling system of the present application includes a frequency conversion controller 11, a seawater subsystem 12, multiple freshwater cooling subsystems 13 and corresponding multiple central coolers (141, 142 and 143), the seawater subsystem 12 is connected to each central cooler (141, 142 and 143) through a seawater circulation pipeline, and each freshwater cooling subsystem 13 is connected to the corresponding central cooler (141, 142 and 143) through a freshwater circulation pipeline. The central coolers (141, 142 and 143) are used to perform heat exchange based on seawater in the seawater circulation pipeline and fresh water in the freshwater circulation pipeline to perform equipment cooling operations; The central cooler (141, 142 and 143) includes a main cooler 141 and several slave coolers (142 and 143). The seawater circulation pipeline is provided with a seawater pump 15 and a control valve 16 corresponding to each slave cooler. The seawater pump 15 is used to control the total water inlet flow of the seawater subsystem 12, and the control valve 16 is used to control the water inlet flow of the corresponding slave cooler. The fresh water circulation pipeline corresponding to each fresh water cooling subsystem 13 is provided with a temperature sensor 17 for real-time detection of the fresh water temperature of the corresponding fresh water circulation pipeline. The frequency conversion controller 11 is respectively connected to the seawater pump 15, the control valve 16 and the temperature sensor 17 for signal connection.

[0021] When the seawater subsystem 12 is in operation, seawater is introduced from the seawater tank 18 into the seawater circulation pipeline, and then the seawater pump 15 and the control valve 16 are controlled based on the frequency conversion control method of the present application, thereby realizing the seawater flow distribution of each central cooler.

[0022] During navigation, the variable frequency controller first measures the primary freshwater temperature of the freshwater cooling subsystem connected to the main cooler. Based on this core temperature, the controller dynamically adjusts the number of seawater pumps running (when connected in parallel) and their operating speed (variable frequency). It should be noted that the main cooler generally provides cooling for the ship's core heat load and is the primary source of cooling during ship operation. Therefore, the main cooler directly controls the seawater flow rate via the seawater pump.

[0023] It's understandable that if the first freshwater temperature is higher than the set value, indicating a high heat dissipation demand for core equipment, the number of operating seawater pumps should be increased or their speeds increased to increase the total seawater flow rate; conversely, the number of pumps should be reduced or their speeds lowered to reduce the total flow rate. This ensures a precisely matched total cooling capacity for the ship's core heat load, avoiding the risk of overcooling and energy waste caused by excessive total seawater flow at low loads associated with traditional fixed-frequency pumps, or insufficient cooling during sudden load increases, significantly improving the operational safety of core equipment and system energy efficiency.

[0024] Simultaneously, in navigation mode, the VFD collects the secondary freshwater temperature of each freshwater cooling subsystem connected to slave coolers (such as generators, auxiliary engines, and other heat loads). For each slave cooler, the controller independently adjusts the control valve opening on its seawater inlet pipe based on its corresponding secondary freshwater temperature.

[0025] Understandably, if the freshwater temperature corresponding to a particular slave cooler is too high, the control valve for that cooler is opened, increasing the seawater flow through it and enhancing its heat exchange capacity; conversely, the valve is closed, reducing the seawater flow. This enables precise, on-demand distribution of seawater flow to different freshwater cooling subsystems (i.e., different devices), resolving the challenge of uneven cooling load distribution when multiple systems are operating in parallel. Each device receives a cooling seawater flow precisely matched to its actual heat dissipation capacity, preventing some devices from being overcooled at low loads while ensuring adequate cooling for all devices under high or sudden load changes, further optimizing system efficiency and device protection.

[0026] Optionally, refer to Figure 3 , controlling the number of seawater pumps opened and the operating speed based on the first fresh water temperature, including: S1101: When multiple seawater pumps are turned on, if a designated seawater pump is running at the lowest speed and a first fresh water temperature is lower than a first set threshold, turn off the designated seawater pump; S1102: When one seawater pump is turned on, if the first fresh water temperature is higher than a second set threshold, increase the number of seawater pumps turned on.

[0027] In navigation mode, the frequency converter can finely adjust the number of seawater pumps activated and their operating speeds based on the primary freshwater temperature corresponding to the main cooler. When multiple seawater pumps are activated and operating in parallel, if a designated pump (such as the last one activated or the least efficient pump) reaches the set minimum safe speed limit, while the primary freshwater temperature corresponding to the main cooler is still below the preset first threshold (indicating excess total cooling capacity), the controller will decisively shut down this designated seawater pump. Conversely, when only one seawater pump is activated, if the primary freshwater temperature rises and exceeds the preset second threshold (usually higher than the first threshold, indicating that even a single pump running at full speed cannot meet the cooling needs of core equipment), the controller will initiate an operation to increase the number of seawater pumps activated (such as turning on another backup pump).

[0028] By fine-tuning the number of seawater pumps that are turned on and their operating speed, the coordinated optimization of the number of operating seawater pumps and the speed of each pump is achieved. Based on the real-time demand of the core heat load, the total power consumption of the seawater pumps is minimized while ensuring sufficient cooling capacity. For example, at low loads, the energy consumption of redundant pumps is directly eliminated by shutting down their energy consumption; when the load increases, the speed of a single pump (which is more efficient) is increased first, and additional pumps are only turned on when the upper speed limit cannot meet the demand. This completely avoids the huge energy waste of traditional fixed-frequency pump groups when all pumps are fully turned on but operate inefficiently under partial load, or when a single fixed-speed pump still needs to run at full speed under partial load. It maximizes the combined energy-saving potential of pump group frequency conversion and number control, and significantly reduces the energy consumption of the ship's core cooling system.

[0029] Optionally, when performing pump group optimization in sailing mode and a seawater pump needs to be shut down, the variable frequency controller prioritizes shutting down the currently active seawater pump with the longest cumulative operating time. The controller continuously records the operating time of each parallel seawater pump. When the pump shutdown condition is triggered, it compares the historical total operating time data of all operating seawater pumps, marks the pump with the longest operating time as "seawater pump to be shut down," and issues a shutdown command. This achieves a balanced service life for the seawater pump group. By prioritizing the shutdown of the pump with the longest cumulative operating time, the system averages the cumulative operating time of all parallel seawater pumps, preventing premature wear or failure of a single pump or a small number of pumps due to long-term continuous operation.

[0030] Optionally, increasing the number of seawater pumps that are turned on includes: According to the accumulated operating time of each of the currently unactivated seawater pumps, the seawater pump with the shortest accumulated operating time is selected for activation.

[0031] Similarly, when the number of seawater pumps needs to be increased during navigation mode, the variable frequency controller will prioritize the currently inactive seawater pump with the shortest cumulative operating time. The controller records the total historical operating time of all standby seawater pumps in real time, automatically compares the data when the pump increase condition is triggered, and starts the idle pump with the shortest operating time. This achieves balanced wear and tear throughout the lifecycle of the seawater pump group. By prioritizing the pump with the shortest operating time, the system forces all parallel pumps to take turns operating, ensuring that the mechanical wear and electrical aging rates of each pump are consistent. While ensuring a seamless increase in cooling capacity, the overall reliability of the pump group is maximized, the rate of sudden failures is reduced, the service life of the equipment is extended, and maintenance costs are reduced.

[0032] Optionally, controlling the opening of a control valve of a corresponding slave cooler based on the second fresh water temperature includes: The opening of the control valve of the slave cooler is dynamically adjusted based on the PID algorithm to ensure that the second fresh water temperature is within the set temperature range.

[0033] In navigation mode, the variable frequency controller uses a PID (proportional-integral-differential) control algorithm to dynamically adjust the opening of the seawater control valve for each slave cooler's corresponding secondary freshwater temperature in real time. A temperature sensor continuously feeds back the secondary freshwater temperature value, which the controller compares with a preset setpoint temperature range (e.g., 75±2°C). The PID algorithm calculates the optimal control valve opening command based on the current temperature deviation (proportional term), historical accumulated deviation (integral term), and temperature trend (differential term), and adjusts the valve opening in real time. If the temperature is too high, the valve opening is increased to increase seawater flow and enhance heat dissipation. If the temperature is too low, the valve opening is decreased to limit flow and avoid overcooling. This strategy achieves precise, stable, and adaptive control of multi-device cooling, allowing it to increase valve openings in advance when loads change suddenly (such as when auxiliary equipment is suddenly loaded), effectively suppressing temperature fluctuations and preventing short-term overheating of the equipment. Even under low loads, the water temperature can be stably controlled within the set range, completely eliminating the periodic temperature fluctuations caused by traditional on-off control. Each slave cooler valve is independently adjusted on demand to avoid frequent valve starts and stops or large movements, reducing mechanical wear and interference with the total seawater flow rate, thereby ensuring the stability of the master cooler control. Ultimately, PID control enables different equipment to achieve "constant temperature-grade" cooling quality under different operating conditions, significantly improving equipment life and operational safety, while further tapping into energy-saving potential by avoiding overcooling.

[0034] For example, based on the above control strategy, assuming that two seawater pumps are turned on, in navigation mode, temperature data is collected through the temperature sensors corresponding to the master and slave coolers, and the temperature sensors corresponding to the master and slave coolers control the frequency conversion of the seawater pumps. The temperature sensor of the slave cooler controls the opening of the corresponding control valve to control the flow of seawater into the slave cooler. At this time, when the seawater pump frequency conversion reaches the lowest speed, the fresh water temperature of the main cooler is still lower than the temperature threshold, then one seawater pump is stopped and water is supplied by the other seawater pump, thereby achieving a more energy-saving effect. When one seawater pump is running, if the temperature of the temperature sensor corresponding to the main cooler exceeds the threshold, the other seawater pump is started, thereby realizing the frequency conversion control of the ship's cooling system.

[0035] S120. When the ship is in the mooring mode, the main cooler is turned off, and the third fresh water temperature of the fresh water cooling subsystem corresponding to the designated slave cooler is collected based on the frequency conversion controller. The number of seawater pumps opened and the operating speed are controlled based on the third fresh water temperature, and the control valve corresponding to the designated slave cooler is controlled to be at the maximum opening.

[0036] Furthermore, when the ship is in mooring mode, the main engine is usually not running, so the main cooler is turned off. At this time, the frequency conversion controller designates a slave cooler that is still in operation (such as a cooler serving a generator or important auxiliary engine) as a reference and collects the third freshwater temperature of its corresponding freshwater cooling subsystem. Based on this third freshwater temperature, the controller dynamically adjusts the number of seawater pumps that are turned on and the operating speed. Its implementation process is similar to that of sailing mode, but the control target is the freshwater temperature of this designated slave cooler. By automatically adapting to the mooring conditions, the focus is on the key equipment that still needs cooling. By controlling the total flow rate of the seawater pump by frequency conversion, the huge energy waste of running the seawater pump at the rated flow rate under low heat load when moored is avoided, significantly reducing the auxiliary energy consumption of the ship when moored.

[0037] Furthermore, in moored mode, the controller sets the corresponding seawater control valve of the designated slave cooler as the benchmark to maximum opening. The variable frequency controller can directly output a control signal to fully open the valve. This ensures maximum seawater flow capacity for the cooler serving this critical equipment, eliminating the resistance that might be introduced by valve throttling. Seawater flow regulation is entirely controlled by the variable frequency pump speed, ensuring maximum cooling reliability and efficiency for this equipment. Simultaneously, the valves of the slave coolers of other non-operating equipment can remain closed or at minimum opening to avoid unnecessary seawater circulation losses.

[0038] Optionally, refer to Figure 4 , based on the third fresh water temperature, controlling the number of seawater pumps opened and the operating speed, including: S1201: When multiple seawater pumps are turned on, if a designated seawater pump is running at the lowest speed and the third fresh water temperature is lower than a first set threshold, turn off the designated seawater pump; S1202: When one seawater pump is turned on, if the third fresh water temperature is higher than the second set threshold, increase the number of seawater pumps turned on.

[0039] When the ship is in berth mode, the variable frequency controller uses a stepped strategy to control the operation of the seawater pumps based on the designated third freshwater temperature from the cooler. When multiple pumps are operating and a pump is at its lowest speed, if the third freshwater temperature falls below the first set threshold for overcooling prevention (e.g., 30°C), the seawater pump with the longest cumulative operating time is shut down first. When only a single pump is operating, if the temperature exceeds the second set threshold for overheating prevention (e.g., 34°C), the standby pump with the shortest cumulative idle time is activated. This design, through dual temperature threshold hysteresis control and a pump rotation mechanism, achieves extreme energy savings while ensuring safe cooling of equipment (such as generators) and avoiding equipment damage caused by frequent pump starts and stops.

[0040] For example, based on the above control strategy, assuming two seawater pumps are running, in mooring mode, the control valve automatically opens to its maximum opening, shutting down the primary cooler. If the freshwater temperature corresponding to the currently active slave cooler falls below a threshold when one seawater pump is operating at its lowest speed, one seawater pump is shut down, and the other pump provides water, achieving even greater energy savings. While one seawater pump is operating, if the temperature sensor exceeds a threshold, the other pump is activated, thus achieving variable frequency control of the ship's cooling system.

[0041] Optionally, in the set operating mode, the present application controls the seawater pump to operate at full load and sets the control valve to the maximum opening.

[0042] When the operator switches to a set operating mode (such as manual operation), the variable frequency controller completely bypasses the aforementioned automatic control logic, directly forcing all seawater pumps to operate at their rated full-load speed (i.e., 100% frequency output), while simultaneously locking all seawater control valves from the coolers to their maximum opening. This design essentially switches the system to a fallback state with maximum cooling capacity, providing absolutely reliable cooling support for ships in extreme operating conditions (such as main engine overload, severe cooler fouling, or automatic control system failure), ensuring that equipment temperatures do not exceed safety limits under any circumstances.

[0043] Optionally, the present application also detects the ship operating condition signal and switches the navigation mode and the mooring mode based on the ship operating condition signal.

[0044] By collecting real-time signals from the vessel's key operating conditions (such as main engine speed, thruster status, GPS speed, and anchor windlass sensor signals), the system automatically determines and switches the cooling system's operating mode. If the main engine is detected to be continuously running and the ship's speed exceeds a set threshold (e.g., 5 knots), it immediately switches to sailing mode, activating the main cooler control logic. If the main engine is detected to be shut down or the vessel has been stationary for longer than a set time (e.g., 30 minutes), it switches to mooring mode, shutting down the main cooler and activating dedicated auxiliary engine cooling logic. This eliminates the potential delays and operational risks associated with manual mode switching (e.g., energy waste from forgetting to switch modes after mooring) and more accurately responds to transient operating conditions (e.g., frequent starts and stops during port entry and exit), ensuring that the cooling strategy is always aligned with the equipment's thermal load. In the event of a sudden failure (e.g., a sudden main engine shutdown during navigation), the system automatically switches to mooring mode within a short period of time, preventing the seawater pump from continuously idling at full load. This brings safety redundancy and energy efficiency optimization to a new level of synergy.

[0045] For the architectural design of multiple freshwater cooling systems corresponding to one seawater system, this application can effectively solve the precise frequency conversion control of seawater pumps by temperature, and at the same time effectively distribute the seawater flow of different coolers, making full use of the seawater volume, thereby achieving a more energy-saving effect.

[0046] Optionally, a real-time digital twin of a ship's cooling system can be constructed, integrating multi-source sensor data such as the pump unit's vibration spectrum, seawater corrosive conductivity, and cooler infrared thermal imaging. This data is then trained using edge computing nodes to create a time-series prediction model. This twin dynamically simulates the physical system's state. When it detects a drop in seawater pump efficiency exceeding a threshold (e.g., a 7% increase in power consumption due to impeller cavitation), it automatically triggers a preventive maintenance work order and simultaneously optimizes PID parameters. For example, in high-algae waters, the integral coefficient can be adaptively reduced to suppress valve oscillation. Alternatively, the remaining life of a seal can be predicted based on control valve actuation frequency and seawater sand content, dynamically adjusting the spare part response level.

[0047] Furthermore, an Organic Rankine Cycle (ORC) power generation module is embedded in the central cooler's high-temperature freshwater circuit (>85°C), enabling intelligent flow diversion by a variable frequency controller. During high-load conditions, the high-temperature freshwater is preferentially directed to the ORC evaporator for power generation (peak output 120kW), with the cooled freshwater (approximately 65°C) then returned to the central cooler. During low-load conditions, the ORC circuit is shut down to ensure basic cooling. Based on the ship's grid load and the lithium battery's SOC, the controller automatically activates the ORC to compensate for power during seawater pump speed reduction. Its condenser is connected in parallel to the seawater subsystem, reducing overall flow requirements. By synergizing the ORC power generation cold end with the seawater pump's variable frequency drive, the triple energy efficiency chain of waste heat recovery, power replenishment, and pump consumption reduction is optimized.

[0048] In the above, when the ship is in navigation mode, the frequency conversion controller is used to collect the first fresh water temperature of the fresh water cooling subsystem corresponding to the main cooler and the second fresh water temperature of the fresh water cooling subsystem corresponding to the slave cooler, and the number of seawater pumps opened and the operating speed are controlled based on the first fresh water temperature, and the opening of the control valve of the corresponding slave cooler is controlled based on the second fresh water temperature; when the ship is in mooring mode, the main cooler is turned off, and the frequency conversion controller is used to collect the third fresh water temperature of the fresh water cooling subsystem corresponding to the designated slave cooler, and the number of seawater pumps opened and the operating speed are controlled based on the third fresh water temperature, and the control valve corresponding to the designated slave cooler is controlled to the maximum opening. By adopting the above technical means, the seawater pumps and coolers of the ship cooling system are precisely controlled by frequency conversion, and the seawater flow of multiple freshwater cooling systems is precisely distributed, thereby avoiding energy waste, improving the control accuracy of the ship cooling system, and improving the stability and reliability of the equipment cooling operation.

[0049] Example 2: Based on the above embodiments, Figure 4 A structural diagram of a frequency conversion control device for a ship cooling system provided in Example 2 of the present application. The ship cooling system of the present application includes a frequency conversion controller, a seawater subsystem, multiple freshwater cooling subsystems, and corresponding multiple central coolers. The seawater subsystem is connected to each central cooler through a seawater circulation pipeline, and each freshwater cooling subsystem is connected to the corresponding central cooler through a freshwater circulation pipeline. The central cooler is used to perform heat exchange based on the seawater in the seawater circulation pipeline and the freshwater in the freshwater circulation pipeline to perform equipment cooling operations; the central cooler includes a master cooler and several slave coolers, the seawater circulation pipeline is provided with a seawater pump and a control valve corresponding to each slave cooler, the seawater pump is used to control the total water inlet flow of the seawater subsystem, the control valve is used to control the water inlet flow of the corresponding slave cooler, and the freshwater circulation pipeline corresponding to each freshwater cooling subsystem is provided with a temperature sensor for real-time detection of the freshwater temperature of the corresponding freshwater circulation pipeline. The frequency conversion controller is respectively connected to the seawater pump, the control valve, and the temperature sensor signal; refer to Figure 4 The frequency conversion control device of the ship cooling system provided in this embodiment specifically includes: a navigation control module 21 and a mooring control module 22.

[0050] The navigation control module 21 is configured to, when the vessel is in navigation mode, collect, based on the frequency conversion controller, a first fresh water temperature of the fresh water cooling subsystem corresponding to the main cooler and a second fresh water temperature of the fresh water cooling subsystem corresponding to the slave cooler, control the number of seawater pumps opened and the operating speed based on the first fresh water temperature, and control the opening of the control valve of the corresponding slave cooler based on the second fresh water temperature; The mooring control module 22 is used to shut down the main cooler when the ship is in mooring mode, collect the third fresh water temperature of the fresh water cooling subsystem corresponding to the designated slave cooler based on the frequency conversion controller, control the number of seawater pumps opened and the operating speed based on the third fresh water temperature, and control the control valve corresponding to the designated slave cooler to the maximum opening.

[0051] Specifically, controlling the number of seawater pumps started and the operating speed based on the first fresh water temperature includes: When multiple seawater pumps are turned on, if the designated seawater pump is running at the lowest speed and the first fresh water temperature is lower than a first set threshold, the designated seawater pump is turned off; In the case of starting one seawater pump, if the first fresh water temperature is higher than the second set threshold, the number of seawater pumps started is increased.

[0052] Increase the number of seawater pumps that are turned on, including: According to the accumulated operating time of each of the currently unactivated seawater pumps, the seawater pump with the shortest accumulated operating time is selected for activation.

[0053] Controlling the opening of a control valve of a corresponding slave cooler based on the second fresh water temperature includes: The opening of the control valve of the slave cooler is dynamically adjusted based on the PID algorithm to ensure that the second fresh water temperature is within the set temperature range.

[0054] Specifically, controlling the number of seawater pumps to be opened and the operating speed based on the third fresh water temperature includes: In the case where multiple seawater pumps are turned on, if the designated seawater pump is running at the lowest speed and the third fresh water temperature is lower than the first set threshold, the designated seawater pump is turned off; In the case of turning on one seawater pump, if the third fresh water temperature is higher than the second set threshold, the number of turned-on seawater pumps is increased.

[0055] In addition, the frequency conversion control device of the ship cooling system also includes: In the set operating mode, the seawater pump is controlled to run at full load and the control valve is set to the maximum opening.

[0056] Detect the ship's operating condition signal and switch between navigation mode and mooring mode based on the ship's operating condition signal.

[0057] In the above, when the ship is in navigation mode, the frequency conversion controller is used to collect the first fresh water temperature of the fresh water cooling subsystem corresponding to the main cooler and the second fresh water temperature of the fresh water cooling subsystem corresponding to the slave cooler, and the number of seawater pumps opened and the operating speed are controlled based on the first fresh water temperature, and the opening of the control valve of the corresponding slave cooler is controlled based on the second fresh water temperature; when the ship is in mooring mode, the main cooler is turned off, and the frequency conversion controller is used to collect the third fresh water temperature of the fresh water cooling subsystem corresponding to the designated slave cooler, and the number of seawater pumps opened and the operating speed are controlled based on the third fresh water temperature, and the control valve corresponding to the designated slave cooler is controlled to the maximum opening. By adopting the above technical means, the seawater pumps and coolers of the ship cooling system are precisely controlled by frequency conversion, and the seawater flow of multiple freshwater cooling systems is precisely distributed, thereby avoiding energy waste, improving the control accuracy of the ship cooling system, and improving the stability and reliability of the equipment cooling operation.

[0058] The frequency conversion control device of the ship cooling system provided in the second embodiment of the present application can be used to execute the frequency conversion control method of the ship cooling system provided in the above-mentioned first embodiment, and has corresponding functions and beneficial effects.

[0059] Example 3: The third embodiment of the present application provides an electronic device, referring to Figure 5 The electronic device includes: a processor 31, a memory 32, a communication module 33, an input device 34, and an output device 35. The number of processors in the electronic device may be one or more, and the number of memories in the electronic device may be one or more. The processor, memory, communication module, input device, and output device of the electronic device may be connected via a bus or other means.

[0060] Memory, as a computer-readable storage medium, can be used to store software programs, computer-executable programs, and modules, such as the program instructions / modules corresponding to the variable frequency control method for a ship cooling system described in any embodiment of the present application (for example, the navigation control module and mooring control module in the variable frequency control device for a ship cooling system). The memory may primarily include a program storage area and a data storage area. The program storage area may store an operating system and at least one application required for a function; the data storage area may store data generated based on device usage. Furthermore, the memory may include high-speed random access memory and non-volatile memory, such as at least one disk storage device, flash memory device, or other non-volatile solid-state memory device. In some instances, the memory may further include memory located remotely from the processor, which can be connected to the device via a network. Examples of such networks include, but are not limited to, the Internet, corporate intranets, local area networks, mobile communication networks, and combinations thereof.

[0061] The communication module is used for data transmission.

[0062] The processor executes various functional applications and data processing of the device by running the software programs, instructions and modules stored in the memory, that is, realizes the above-mentioned variable frequency control method of the ship cooling system.

[0063] The input device can be used to receive input digital or character information and generate key signal input related to user settings and function control of the device. The output device can include a display device such as a display screen.

[0064] The electronic device provided above can be used to execute the frequency conversion control method for the ship cooling system provided in the above embodiment 1, and has corresponding functions and beneficial effects.

[0065] Example 4: An embodiment of the present application also provides a storage medium containing computer-executable instructions, which, when executed by a computer processor, are used to execute a variable frequency control method for a ship cooling system. The variable frequency control method for a ship cooling system includes: when the ship is in navigation mode, based on the frequency conversion controller, collecting the first fresh water temperature of the fresh water cooling subsystem corresponding to the main cooler and the second fresh water temperature of the fresh water cooling subsystem corresponding to the slave cooler, controlling the number of seawater pumps opened and the operating speed based on the first fresh water temperature, and controlling the opening of the control valve of the corresponding slave cooler based on the second fresh water temperature; when the ship is in mooring mode, closing the main cooler, collecting the third fresh water temperature of the fresh water cooling subsystem corresponding to the specified slave cooler based on the frequency conversion controller, controlling the number of seawater pumps opened and the operating speed based on the third fresh water temperature, and controlling the control valve corresponding to the specified slave cooler to be maximum opening.

[0066] Storage medium - any of various types of memory devices or storage devices. The term "storage medium" is intended to include: installation media, such as CD-ROMs, floppy disks, or tape drives; computer system memory or random access memory, such as DRAM, DDR RAM, SRAM, EDO RAM, Rambus RAM, etc.; non-volatile memory, such as flash memory, magnetic media (such as hard disks or optical storage); registers or other similar types of memory elements, etc. Storage media may also include other types of memory or combinations thereof. In addition, the storage medium may be located in the first computer system in which the program is executed, or it may be located in a different second computer system that is connected to the first computer system via a network (such as the Internet). The second computer system can provide program instructions to the first computer for execution. The term "storage medium" may include two or more storage media residing in different locations (e.g., in different computer systems connected via a network). The storage medium may store program instructions (e.g., embodied as a computer program) that can be executed by one or more processors.

[0067] Of course, the storage medium containing computer-executable instructions provided in an embodiment of the present application, whose computer-executable instructions are not limited to the frequency conversion control method of the ship cooling system as described above, can also execute related operations in the frequency conversion control method of the ship cooling system provided in any embodiment of the present application.

[0068] The frequency conversion control device, storage medium and electronic device of the ship cooling system provided in the above embodiments can execute the frequency conversion control method of the ship cooling system provided in any embodiment of the present application. For technical details not described in detail in the above embodiments, please refer to the frequency conversion control method of the ship cooling system provided in any embodiment of the present application.

[0069] The above are only preferred embodiments of the present application and the technical principles employed. The present application is not limited to the specific embodiments described herein, and various obvious changes, readjustments, and substitutions that are possible for those skilled in the art will not depart from the scope of protection of the present application. Therefore, although the present application has been described in more detail through the above embodiments, the present application is not limited to the above embodiments and may include more other equivalent embodiments without departing from the concept of the present application. The scope of the present application is determined by the scope of the claims.

Claims

1. A variable frequency control method for a ship cooling system, the ship cooling system comprising a variable frequency controller, a seawater subsystem, multiple freshwater cooling subsystems, and corresponding multiple central coolers, the seawater subsystem being connected to each of the central coolers via a seawater circulation pipeline, and each of the freshwater cooling subsystems being connected to a corresponding central cooler via a freshwater circulation pipeline, the central coolers being configured to perform equipment cooling operations by exchanging heat between seawater in the seawater circulation pipeline and freshwater in the freshwater circulation pipeline; It is characterized by: The central cooler includes a main cooler and several slave coolers. The seawater circulation pipeline is provided with a seawater pump and a control valve corresponding to each of the slave coolers. The seawater pump is used to control the total water inlet flow of the seawater subsystem, and the control valve is used to control the water inlet flow of the corresponding slave cooler. The fresh water circulation pipeline corresponding to each of the fresh water cooling subsystems is provided with a temperature sensor for real-time detection of the fresh water temperature of the corresponding fresh water circulation pipeline. The frequency conversion controller is respectively connected to the seawater pump, the control valve and the temperature sensor for signal connection; The frequency conversion control method of the ship cooling system includes: When the ship is in sailing mode, the frequency conversion controller collects a first fresh water temperature of the fresh water cooling subsystem corresponding to the main cooler and a second fresh water temperature of the fresh water cooling subsystem corresponding to the slave cooler, controls the number of seawater pumps to be opened and the operating speed based on the first fresh water temperature, and controls the opening of the control valve of the corresponding slave cooler based on the second fresh water temperature; When the ship is in mooring mode, the main cooler is turned off, and the third fresh water temperature of the fresh water cooling subsystem corresponding to the designated slave cooler is collected based on the frequency conversion controller. The number of openings and the operating speed of the seawater pump are controlled based on the third fresh water temperature, and the control valve corresponding to the designated slave cooler is controlled to be at the maximum opening.

2. The frequency conversion control method for a ship cooling system according to claim 1, characterized in that: The controlling the number of activations and the operating speed of the seawater pump based on the first fresh water temperature includes: In the case where a plurality of seawater pumps are turned on, if the designated seawater pump is running at the lowest speed and the first fresh water temperature is lower than a first set threshold, turning off the designated seawater pump; In the case of turning on one of the seawater pumps, if the first fresh water temperature is higher than a second set threshold, the number of the turned-on seawater pumps is increased.

3. The frequency conversion control method for a ship cooling system according to claim 2, characterized in that: The increasing the number of times the seawater pump is turned on includes: According to the accumulated operating time of each of the currently unactivated seawater pumps, the seawater pump with the shortest accumulated operating time is selected for activation.

4. The frequency conversion control method for a ship cooling system according to claim 1, characterized in that: The controlling the number of activations and the operating speed of the seawater pump based on the third fresh water temperature includes: In the case where a plurality of seawater pumps are turned on, if the designated seawater pump is running at the lowest speed and the third fresh water temperature is lower than a first set threshold, turning off the designated seawater pump; In the case of turning on one of the seawater pumps, if the third fresh water temperature is higher than the second set threshold, the number of the turned-on seawater pumps is increased.

5. The frequency conversion control method for a ship cooling system according to claim 1, characterized in that: The controlling the opening of the control valve of the corresponding slave cooler based on the second fresh water temperature includes: The opening of the control valve of the slave cooler is dynamically adjusted based on a PID algorithm to ensure that the second fresh water temperature is within a set temperature range.

6. The frequency conversion control method for a ship cooling system according to claim 1, characterized in that: The method further comprises: In the set operation mode, the seawater pump is controlled to operate at full load, and the control valve is set to the maximum opening.

7. The frequency conversion control method for a ship cooling system according to claim 1, characterized in that: The method further comprises: A ship operating condition signal is detected, and the navigation mode and the mooring mode are switched based on the ship operating condition signal.

8. A frequency conversion control device for a ship cooling system, the ship cooling system comprising a frequency conversion controller, a seawater subsystem, multiple freshwater cooling subsystems, and corresponding multiple central coolers, the seawater subsystem being connected to each of the central coolers via a seawater circulation pipeline, and each of the freshwater cooling subsystems being connected to a corresponding central cooler via a freshwater circulation pipeline, the central coolers being configured to perform equipment cooling operations by exchanging heat between seawater in the seawater circulation pipeline and freshwater in the freshwater circulation pipeline; It is characterized by: The central cooler includes a main cooler and several slave coolers. The seawater circulation pipeline is provided with a seawater pump and a control valve corresponding to each of the slave coolers. The seawater pump is used to control the total water inlet flow of the seawater subsystem, and the control valve is used to control the water inlet flow of the corresponding slave cooler. The fresh water circulation pipeline corresponding to each of the fresh water cooling subsystems is provided with a temperature sensor for real-time detection of the fresh water temperature of the corresponding fresh water circulation pipeline. The frequency conversion controller is respectively connected to the seawater pump, the control valve and the temperature sensor for signal connection; The frequency conversion control device of the ship cooling system includes: a navigation control module, configured to, when the ship is in navigation mode, collect, based on the frequency conversion controller, a first fresh water temperature of the fresh water cooling subsystem corresponding to the main cooler and a second fresh water temperature of the fresh water cooling subsystem corresponding to the slave cooler, control the number of seawater pumps to be opened and the operating speed based on the first fresh water temperature, and control the opening of the control valve of the corresponding slave cooler based on the second fresh water temperature; The mooring control module is used to, when the ship is in mooring mode, shut down the main cooler, collect the third fresh water temperature of the fresh water cooling subsystem corresponding to the designated slave cooler based on the frequency conversion controller, control the number of seawater pumps opened and the operating speed based on the third fresh water temperature, and control the control valve corresponding to the designated slave cooler to the maximum opening.

9. An electronic device, characterized in that: include: memory and one or more processors; The memory is used to store one or more programs; When the one or more programs are executed by the one or more processors, the one or more processors implement the variable frequency control method for a ship cooling system according to any one of claims 1 to 7.

10. A storage medium containing computer-executable instructions, characterized in that: When executed by a computer processor, the computer executable instructions are used to execute the frequency conversion control method for a ship cooling system according to any one of claims 1 to 7.

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