Oil tanker cargo oil variable condition adaptive heating control system

Abstract

The present application relates to the field of cargo oil heating control, and discloses a cargo oil variable condition self-adaptive heating control system, which comprises a heating partition module, a parameter acquisition module, a heat flow verification module, a topology identification module and a heating control module. The heating partition module establishes a preset positional relationship between each heating zone and a key pumping area, the parameter acquisition module acquires heating zone operating state, key pumping area cargo oil state, ship attitude data, unloading demand data and verification channel data. The heat flow verification module forms a controlled low flow verification process, and the heating control module obtains verification equivalent pressure loss according to the verification channel data and the unloading demand data, and determines pumping margin, heating demand weight and abnormal reason type in combination with heat response results and heat flow improvement results, and outputs a control instruction. The present application is used for improving the correspondence between cargo oil heating control and unloading pumping demand of an oil tanker.

Description

Technical Field

[0001] This invention relates to the field of cargo oil heating control, specifically an adaptive heating control system for cargo oil tankers operating under varying conditions. Background Technology

[0002] Currently, when tankers transport high-viscosity crude oil or crude oil with specific unloading temperature requirements, the cargo oil tanks and related pipelines need to be heated during the navigation, unloading preparation, and unloading phases. The temperature and flow resistance of the cargo oil vary depending on its height, longitudinal position, and proximity to pipelines within the tanks, influenced by factors such as liquid level, ship's trim and heel angles, and the arrangement of heating components. This is particularly true in areas near the pump inlet, the bilge flow channels, and the main cargo oil inlet area, where the condition of the cargo oil directly affects the unloading pump suction conditions, pipeline pressure loss, and bilge residue.

[0003] For the aforementioned cargo oil heating control on oil tankers, existing applications typically supply heat to the cargo oil tanks via steam heating coils, thermal oil heating coils, or electric heat tracing components. Control is then based on the cargo oil tank temperature detection points, heating medium inlet parameters, heating medium outlet parameters, and valve openings. After receiving temperature data, the control equipment uses the average tank temperature, selected measurement point temperature, or target unloading temperature as the basis for adjustment, uniformly increasing or decreasing the steam flow rate, thermal medium flow rate, or equivalent heating power in the corresponding heating zone. Before unloading, operators also preheat the area near the pump suction port or the cargo oil pipeline inlet, taking into account the cargo oil temperature, expected unloading time, and experienced parameters.

[0004] The aforementioned control methods primarily rely on temperature results to determine the heating status. However, a rise in temperature does not necessarily correspond to a reduction in pressure loss in key pumping areas. When the cargo oil tank level drops or the ship's attitude changes, the effective submersion of some heating components will change. Areas that previously provided heating may no longer be able to improve the flow conditions near the pump inlet, the bilge channel, or the cargo oil main inlet under current operating conditions. Furthermore, existing control processes typically lack low-flow verification data under abnormal unloading conditions, making it difficult to correlate verification channel pressure and flow rate with target unloading requirements. This results in insufficient correspondence between heating output distribution and pumping margin gaps, and makes it difficult to distinguish between insufficient heating, heat exchange failure, pipeline inlet limitations, and insufficient effective submersion.

[0005] Therefore, the present invention provides an adaptive heating control system for oil tanker cargo oil changing operating conditions to overcome the shortcomings of the prior art. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides an adaptive heating control system for oil tanker cargo oil under varying operating conditions. This system solves the problem in existing oil tanker cargo oil heating control systems where relying solely on temperature adjustment makes it difficult to accurately correspond to the actual pumping status of key pumping areas, resulting in a mismatch between heating output distribution and unloading pumping requirements.

[0007] To achieve the above objectives, the present invention provides the following technical solution: An adaptive heating control system for cargo oil tankers under varying operating conditions includes: The heating zoning module is used to divide the heating components in the cargo oil tank into multiple independently adjustable heating zones and establish a preset positional relationship between each heating zone and the key pumping area. The parameter acquisition module is used to collect and time-mark the operating status of the heating zone, the status of cargo oil in key pumping areas, ship attitude data, unloading demand data, and verification channel data. The thermal flow verification module is used to establish a controlled low-flow verification process under abnormal unloading conditions. The topology identification module is used to determine the effective immersion state and effective heat transfer relationship based on the preset positional relationship, the ship attitude data, thermal response results, and heat flow improvement results. The heating control module is used to calculate the effective heat input based on the operating status of the heating zone, obtain the thermal response result based on the effective heat input and the cargo oil status of the key pumping area, obtain the verification equivalent pressure loss based on the verification channel data and the unloading demand data, and determine the pumping margin, heating demand weight, and abnormal cause type based on the effective heat transfer relationship and the verification equivalent pressure loss, and output control commands.

[0008] By adopting the above technical solution, the heating control process does not use the average temperature of the cargo oil tank as the sole control object, but incorporates the pumpable state of key pumping areas into the control basis; the heat flow verification module forms a controlled low flow verification process under abnormal unloading conditions, and the heating control module obtains the verification equivalent pressure loss based on the verification channel data and unloading demand data, and determines the heat flow improvement result based on the change of the verification equivalent pressure loss; the topology identification module determines the effective immersion state and effective heat transfer relationship based on the preset position relationship, ship attitude data, thermal response results and heat flow improvement results; the heating control module then determines the pumping margin, heating demand weight and abnormal cause type based on the effective heat transfer relationship and the verification equivalent pressure loss, thereby distributing the heating output to the heating zone that has an effective effect on the key pumping area, and obtaining a zoned heating control effect that adapts to changes in liquid level, changes in ship attitude and changes in unloading demand.

[0009] Preferably, the heating zone module for dividing heating zones and establishing preset positional relationships specifically includes: The heating components are divided into the bilge pump suction port heating zone, the bilge far end heating zone, the bulkhead adjacent heating zone, the central insulation heating zone, and the cargo oil pipeline inlet preheating zone. Each of the heating zones is connected to an independent regulating valve, which is used to change the steam flow rate, heat transfer medium flow rate, or equivalent heating power of the corresponding heating zone; The preset positional relationships include the height position, longitudinal position, lateral position, total length of heat exchange components, distance relationship with the area adjacent to the pump inlet and the bilge flow channel area of ​​each heating zone, and pipeline relationship with the cargo oil main inlet area.

[0010] By adopting the above technical solution, the heating components in the cargo oil tank are divided into zones according to their functional relationship with the area adjacent to the pump suction port, the bilge flow channel area, and the cargo oil main inlet area. This allows different heating zones to receive control commands independently and provides a structural basis for determining the subsequent effective immersion state and effective heat transfer relationship.

[0011] Preferably, the parameter acquisition module is used to acquire data and perform time stamping, specifically including: Collect data on valve opening, steam inlet pressure, steam inlet temperature, condensate outlet temperature, condensate flow rate, and drainage status for each heating zone; Collect the following data: temperature in the area near the pump suction inlet, temperature in the bilge flow channel area, temperature in the cargo oil main inlet area, cargo oil level, ship trim angle, ship heel angle, estimated unloading time, target unloading flow rate, allowable suction conditions of the unloading pump, target unloading temperature, and target unloading viscosity. The inlet pressure, outlet pressure, inlet temperature, outlet temperature, and verification flow rate of the heat flow verification module are collected. When the detected value exceeds the sensor's range, the signal is interrupted, or the continuous sampling value does not meet the preset range of change, the corresponding data will be marked as invalid data.

[0012] By adopting the above technical solution, the system places the operating status of the heating zone, the cargo oil status of the key pumping area, the ship attitude data, the unloading demand data, and the verification channel data under the same time reference, so that the effective heat input, heat response results, verification equivalent pressure loss changes, and ship attitude changes can establish a corresponding relationship within the same control cycle, reducing the impact of invalid data on the control output.

[0013] Preferably, the heat flow verification module for forming the controlled low flow verification process specifically includes: It is equipped with a low-flow drive unit, a cleanable measuring pipe section, a differential pressure detection unit, a temperature detection unit, an isolation valve group, a bypass valve group, a heat tracing unit, a drain port, and a flushing port; Connect the inlet of the heat flow verification module to the area adjacent to the pump suction port, the bilge flow channel area, or the cargo oil main inlet area, and make the outlet of the heat flow verification module return to the same cargo oil tank or the same cargo oil circulation loop. When the pressure difference between the inlet and outlet of the verification channel exceeds a preset safety differential pressure threshold, or the verification flow rate is lower than a preset minimum verification flow rate threshold, or the verification channel temperature is lower than a preset minimum channel temperature threshold, the heating control module stops the operation of the heat flow verification module and controls the isolation valve group to close.

[0014] Furthermore, the preset safety differential pressure threshold is determined based on the rated pressure of the cleanable measurement section and the allowable pressure of the cargo oil pump; the preset minimum verification flow rate threshold is determined based on the lower limit of the measurable flow rate of the cleanable measurement section; and the preset minimum channel temperature threshold is determined based on the target unloading temperature of the cargo oil and the heat tracing capacity of the verification channel.

[0015] By adopting the above technical solution, the system can obtain the verification channel data of the cargo oil corresponding to the key pumping area without entering the normal unloading main channel. By limiting the safety differential pressure, minimum verification flow rate and minimum channel temperature, the controlled low flow verification process is matched with the safety boundary of cargo oil pumping.

[0016] Preferably, the heating control module for calculating the effective heat input specifically includes: The effective heat input of each heating zone is obtained based on the steam inlet enthalpy, condensate outlet enthalpy, condensate mass flow rate, and effective heating correction factor. When using heat transfer oil heating, the effective heat input of each heating zone is obtained based on the inlet temperature of the heat transfer medium, the outlet temperature of the heat transfer medium, the circulation flow rate, and the specific heat capacity of the heat transfer medium. The effective heat input is used to obtain the thermal response result, determine the heat flow improvement result, and determine the type of the abnormality cause.

[0017] By adopting the above technical solution, the system uses the actual heat transferred from the heating zone to the cargo oil side as the basis for control calculation, so that valve action, condensate status, steam supply status or heat transfer medium heat exchange status are included in the same effective heat input calculation process, thereby improving the consistency of calculation of heating demand weight and abnormal cause type.

[0018] Preferably, the heating control module for obtaining the thermal response result specifically includes: Before performing thermal response identification, determine whether the target heating zone meets the thermal pulse access conditions; When the target heating zone meets the thermal pulse access condition, the independent regulating valve of the target heating zone is controlled to change its opening within a preset disturbance range, and a controlled thermal pulse is formed. When the target heating zone does not meet the thermal pulse access condition, the valve fine-tuning response, natural heat dissipation response, or existing low-flow circulation response during the normal heating process are used as alternative perturbation inputs. The thermal response coefficient is obtained based on the temperature change of the key pumping area before and after thermal response identification and the effective heat input, and the thermal response coefficient is used as the thermal response result.

[0019] Furthermore, the thermal pulse access conditions may include: the effective immersion factor of the target heating zone is not lower than a preset effective immersion threshold; the representative temperature of the target key pumping area is not higher than the upper limit of the cargo's allowable temperature; the steam inlet pressure is not lower than a preset lower limit of steam pressure; the condensate discharge status is normal; and the heat flow verification module is in an isolated, drainable, and flushable state. When the thermal response coefficient is lower than the preset thermal response threshold, the thermal response status of the corresponding target heating zone in the corresponding key pumping area can be marked as a low response state. The preset effective immersion threshold is determined based on the arrangement of the heat exchange components in the heating zone; the upper limit of the cargo's allowable temperature is determined based on the cargo oil loading data, unloading temperature requirements, and cargo heating restrictions; the preset lower limit of steam pressure is determined based on the lowest pressure at which the ship's steam heating system can stably supply heat; and the preset thermal response threshold is determined based on historical heating records of similar cargo oil, sea trial records, or initial identification results after loading.

[0020] By adopting the above technical solution, the system obtains thermal response results by using controlled thermal pulses when the thermal pulse access conditions are met, and obtains thermal response results by using alternative perturbation inputs when the thermal pulse access conditions are not met, so that the thermal response identification process can adapt to different heating stages and safety states.

[0021] Preferably, the heating control module for obtaining the verification equivalent pressure loss specifically includes: The controlled low-flow verification process is initiated before and after the thermal response identification. Based on the verification channel inlet pressure, verification channel outlet pressure, verification flow rate, target unloading equivalent demand flow rate, and verification channel flow rate index, the low flow rate verification pressure difference is converted into the verification equivalent pressure loss under the target unloading equivalent demand flow rate. The heat flow improvement result is determined based on the verified equivalent pressure loss change, and the verified equivalent pressure loss is used to determine the pumping margin and the type of anomaly cause.

[0022] Furthermore, when the verified equivalent pressure loss is higher than the preset pressure loss threshold, it can be determined that the oil in the corresponding key pumping area has an abnormal pressure loss after being converted to the target unloading equivalent demand flow rate; the preset pressure loss threshold is determined based on the target unloading viscosity of the oil, the verification channel structure parameters, and the target unloading flow rate.

[0023] By adopting the above technical solution, the system converts the pressure difference and flow data obtained in the controlled low flow verification process into the verification equivalent pressure loss under the target unloading equivalent demand flow, and generates heat flow improvement results based on the changes in verification equivalent pressure loss, so as to establish a correspondence between temperature response and pumping improvement.

[0024] Preferably, the topology identification module for determining the effective immersion state and the effective heat transfer relationship specifically includes: The length of the heat exchange component currently covered by cargo oil in each heating zone is determined based on the preset positional relationship, the cargo oil level in the ship attitude data, the ship's pitch angle, and the ship's roll angle. The heat transfer effectiveness correction factor is determined by combining the condensate state, thermal response state, and historical effective heat transfer state. The effective immersion factor is determined based on the length of the heat exchange component, the total length of the heat exchange component, and the heat exchange effectiveness correction factor. The effective heat transfer relationship is determined based on the effective immersion factor, the structural correlation factor, the normalized thermal response coefficient corresponding to the thermal response result, and the normalized heat flow improvement coefficient corresponding to the heat flow improvement result.

[0025] Furthermore, when the effective heat transfer relationship is lower than the preset effective transfer threshold, the relationship between the corresponding heating zone and the key pumping area can be marked as a low effective relationship and transferred; the preset effective transfer threshold is determined based on the cargo oil tank structure, the arrangement of the heating zone, and historical effective heating results.

[0026] By adopting the above technical solution, the system combines the actual immersion changes caused by liquid level and ship attitude, the structural correlation of heating zone, thermal response coefficient and heat flow improvement coefficient into an effective heat transfer relationship, so that the heating control module distributes heat output according to the current effective relationship.

[0027] Preferably, the heating control module is used to determine the pumping margin and the heating demand weight, specifically including: The pumping margin of the critical pumping area is calculated based on the verified equivalent pressure loss, pipeline pressure loss, static pressure correction term and allowable pressure loss boundary. A pumping margin gap is formed when the pumping margin is lower than the target pumping margin; The heating demand weights for each heating zone are generated based on the demand weights of key pumping areas, the pumping margin gap, and the effective heat transfer relationship. When the expected unloading time is earlier than scheduled, increase the demand weight of the area near the pump suction port and the cargo oil main inlet area; when the expected unloading time is later than scheduled, decrease the demand weight of the central insulation and heating area and the heating area near the bulkhead.

[0028] By adopting the above technical solution, the system generates heating demand weights based on pumping margin gaps rather than a single average temperature deviation, and allocates control commands for each heating zone according to the demand weights of key pumping areas and the effective heat transfer relationship, so that the heating target matches the pumping demand during the unloading stage.

[0029] Preferably, the heating control module for determining the type of the abnormality and outputting the control command specifically includes: The type of abnormal cause is determined based on the effective heat input, the heat response coefficient as the result of the heat response, the heat flow improvement coefficient as the result of the heat flow improvement, the verified equivalent pressure loss, the effective immersion factor obtained from the effective immersion state, the condensate state, and the pipe inlet state. The types of abnormal causes include insufficient heating, heat exchange failure, effective thermal response but insufficient pumping improvement, pipeline inlet restriction, and insufficient effective immersion. Based on the heating demand weight, control gain, anomaly suppression coefficient, and anomaly suppression term, the control command for the next control cycle of each heating zone is output. The control command includes the steam regulating valve opening, the heat transfer medium regulating valve opening, or the equivalent heating power command.

[0030] Furthermore, the logic for determining the type of abnormal cause may include: when the effective heat input is lower than a preset effective heat input threshold and the temperature change representing the key pumping area is lower than a preset temperature change threshold, it is determined to be a case of insufficient heating; when the effective heat input is not lower than a preset effective heat input threshold and the thermal response coefficient is lower than a preset thermal response threshold, it is determined to be a case of heat exchange failure; when the thermal response coefficient is not lower than a preset thermal response threshold and the heat flow improvement coefficient is lower than a preset heat flow improvement threshold, it is determined to be a case of effective thermal response but insufficient pumping improvement; when the pipeline pressure loss in the cargo oil main inlet area is higher than a preset pipeline pressure loss threshold, it is determined to be a case of pipeline inlet restriction; when the effective immersion factor is lower than a preset effective immersion threshold, it is determined to be a case of insufficient effective immersion; the above-mentioned preset thresholds can be set accordingly based on the design heat exchange load, temperature detector resolution, historical data, and structural parameters.

[0031] By adopting the above technical solution, the system distinguishes the types of abnormal causes based on effective heat input, thermal response coefficient, heat flow improvement coefficient, verification equivalent pressure loss, effective immersion factor, condensate state, and pipeline inlet state. It also restricts heating zones that are not suitable for further increasing heat output through abnormal suppression terms, so that the control command of the next control cycle matches the abnormal cause type and heating demand weight.

[0032] This invention provides an adaptive heating control system for cargo oil tankers operating under varying conditions. It offers the following advantages: 1. This invention divides the heating components in the cargo oil tank into multiple independently adjustable heating zones through a heating zoning module. A parameter acquisition module collects the operating status of the heating zones, the cargo oil status in key pumping areas, ship attitude data, and unloading demand data. This allows heating control to be adjusted based on the overall temperature of the cargo oil tank, rather than solely on the overall temperature. Instead, it enables zoned control by considering the actual conditions of the areas near the pump inlet, the bilge flow channel, and the cargo oil main inlet area. This improves the correspondence between heating output and unloading pumping requirements.

[0033] 2. This invention establishes a controlled low-flow verification process under abnormal unloading conditions through a heat flow verification module. The heating control module obtains the verification equivalent pressure loss based on verification channel data and unloading demand data, enabling the system to determine the flow constraint state of key pumping areas before unloading or under abnormal unloading conditions. The heat flow improvement result is then determined by combining the changes in the verification equivalent pressure loss. This allows the heating control process to consider both temperature response and pumping improvement results, thereby reducing control deviations caused by judging the heating effect solely by temperature increase.

[0034] 3. This invention uses a topology identification module to determine the effective submersion state and effective heat transfer relationship based on preset positional relationships, ship attitude data, thermal response results, and heat flow improvement results. The heating control module then outputs control commands based on the effective heat transfer relationship, verified equivalent pressure loss, pumping margin, and anomaly cause type. This enables the system to identify operating states such as insufficient effective submersion, heat exchange failure, and pipeline inlet restrictions, and to suppress heating zones where further heat output is not suitable. This improves the adaptability of heating control under conditions of liquid level changes, ship attitude changes, and unloading demand changes. Attached Figure Description

[0035] Figure 1 This is a framework diagram of the tanker cargo oil changing condition adaptive heating control system of the present invention; Figure 2 This is a flowchart of the adaptive heating control method for oil tanker cargo oil changing operating conditions according to the present invention; Figure 3 This is a flowchart of the process for collecting operating parameters and calculating heat in step S100 of the present invention. Figure 4 This is a flowchart of the thermal response identification and heat flow verification process in step S200 of the present invention. Figure 5 This is a flowchart of the effective heating topology identification process in step S300 of the present invention; Figure 6 This is a flowchart of the calculation of pumping margin and heating requirement in step S400 of the present invention. Figure 7 This is a flowchart of cause classification and heating control in step S500 of the present invention; Figure 8This is a graph showing the variation of pumping margin in the key pumping area of ​​the present invention. Figure 9 This is a comparison curve between the conventional temperature control method of this invention and the control method of this invention. Detailed Implementation

[0036] The technical solutions in 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, and 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.

[0037] See attached document Figure 1 The present invention provides an adaptive heating control system for oil tanker cargo oil changing operating conditions, which includes a heating zoning module, a parameter acquisition module, a heat flow verification module, a topology identification module and a heating control module.

[0038] The heating zoning module divides the heating components within the cargo oil tank into multiple independently adjustable heating zones. The heating components include steam heating coils, heat transfer oil heating coils, and electric heat tracing exchangers. The heating zoning module includes a bilge pump suction inlet heating zone, a bilge distal end heating zone, a bulkhead adjacent heating zone, a central insulation heating zone, and a cargo oil pipeline inlet preheating zone. Each heating zone is connected to an independent regulating valve, which receives control commands from the heating control module and adjusts the steam flow rate, heat transfer medium flow rate, or equivalent heating power for the corresponding heating zone.

[0039] The heating zone module also includes inlet and outlet detection components corresponding to each heating zone. For steam heating, the inlet detection components include a steam inlet pressure detector and a steam inlet temperature detector, while the outlet detection components include a condensate outlet temperature detector, a condensate flow rate detector, and a condensate status detector. For heat transfer oil heating, the inlet detection components include a heat transfer medium inlet temperature detector and an inlet pressure detector, while the outlet detection components include a heat transfer medium outlet temperature detector and a circulation flow rate detector. The detection results from these components are transmitted to the parameter acquisition module.

[0040] The heating zoning module establishes preset positional relationships between each heating zone and the cargo oil tank structure. These preset relationships include the heating zone's height, longitudinal position, lateral position within the cargo oil tank, total length of heat exchange components, distance from the area adjacent to the pump suction inlet, distance from the bilge flow channel area, and pipeline relationship with the cargo oil main inlet area. These preset positional relationships are invoked by the topology identification module to determine the effective heating effect of each heating zone on key pumping areas under current operating conditions.

[0041] The parameter acquisition module is used to collect the operating condition data required for the heating control of cargo oil in oil tankers. The module includes heating status acquisition units, cargo oil status acquisition units, ship attitude acquisition units, unloading requirement acquisition units, and verification channel acquisition units. The parameter acquisition module connects to the corresponding detection components via the ship's automation control network, fieldbus, analog input interfaces, or digital input interfaces.

[0042] The heating status acquisition unit collects valve opening, steam inlet pressure, steam inlet temperature, condensate outlet temperature, condensate flow rate, and drainage status for each heating zone, forming the operating status of the heating zone. The cargo oil status acquisition unit collects cargo oil temperatures at different heights and locations within the cargo oil tanks, including at least the temperature near the pump suction inlet, the temperature in the bilge flow channel, and the temperature at the cargo oil main inlet, forming the cargo oil status for key pumping areas. The ship attitude acquisition unit collects cargo oil levels, ship heel and roll angles, forming ship attitude data. The unloading demand acquisition unit collects estimated unloading time, target unloading flow rate, allowable suction conditions for the unloading pump, target unloading temperature, and target unloading viscosity, forming unloading demand data. The verification channel acquisition unit collects inlet pressure, outlet pressure, inlet temperature, outlet temperature, and verification flow rate of the heat flow verification module, forming verification channel data.

[0043] The parameter acquisition module timestamps the operating status of the heating zone, the cargo oil status in the key pumping area, ship attitude data, unloading demand data, and verification channel data. This timestamping enables the heating control module to match the effective heat input to the heating zone, temperature changes in the key pumping area, changes in the verification equivalent pressure loss, and changes in ship attitude within the same control cycle. The parameter acquisition module also verifies the validity of the acquired data. When a detected value exceeds the sensor's range, the signal is interrupted, or continuous sampling values ​​do not meet the preset variation range, the corresponding data is marked as invalid, and this invalid data status is transmitted to the heating control module.

[0044] The thermal flow validation module is used to establish a controlled low-flow validation process under abnormal unloading conditions, enabling the parameter acquisition module to obtain validation channel data. The thermal flow validation module includes a low-flow drive unit, a cleanable measurement section, a differential pressure detection unit, a temperature detection unit, an isolation valve assembly, a bypass valve assembly, a heat tracing unit, a drain port, and a flushing port. The low-flow drive unit drives the cargo oil through the cleanable measurement section at a low flow rate. The cleanable measurement section has known flow resistance characteristics and can be a straight pipe measurement section, a Venturi measurement section, or a detachable flow-limiting measurement section. The differential pressure detection unit detects the pressure difference between the inlet and outlet of the cleanable measurement section. The temperature detection unit detects the inlet and outlet temperatures of the validation channel.

[0045] The inlet of the thermal flow verification module is connected to the area adjacent to the pump suction port, the bilge flow channel area, or the cargo oil main inlet area, while the outlet flows back to the same cargo oil tank or the same cargo oil circulation loop. The thermal flow verification module is not used as the normal main unloading channel; it operates briefly during the thermal response identification, pumping status confirmation, or anomaly cause determination phases. An isolation valve assembly is used to isolate the thermal flow verification module from the cargo oil main pipeline. A bypass valve assembly is used to create a bypass flow path when the pressure difference in the verification channel is abnormal. A heat tracing unit is used to insulate the cleanable measuring pipe sections and low-point pipe sections in the verification channel. A drain port is used to drain residual cargo oil from the verification channel. A flush port is used to flush the verification channel during cargo changes, maintenance, or when the verification channel resistance is abnormal.

[0046] Before the thermal flow verification module operates, the heating control module checks the status of the isolation valve group, bypass valve group, heat tracing unit, drain port, and flushing port. During operation, the verification channel acquisition unit continuously collects inlet pressure, outlet pressure, and verification flow rate. When the difference between the inlet and outlet pressures of the verification channel exceeds a preset safe differential pressure threshold, or the verification flow rate is lower than a preset minimum verification flow rate threshold, or the verification channel temperature is lower than a preset minimum channel temperature threshold, the heating control module stops the thermal flow verification module and controls the isolation valve group to close. The preset safe differential pressure threshold is determined based on the rated pressure of the cleanable measurement section and the allowable pressure of the cargo oil pump; the preset minimum verification flow rate threshold is determined based on the lower limit of the measurable flow rate of the cleanable measurement section; and the preset minimum channel temperature threshold is determined based on the target unloading temperature of the cargo oil and the heat tracing capacity of the verification channel.

[0047] The topology identification module determines the effective immersion state of each heating zone under current operating conditions based on preset positional relationships, ship attitude data, thermal response results, and heat flow improvement results. It also determines the effective heat transfer relationship between each heating zone and the critical pumping area. The topology identification module stores cargo oil tank structural data and heating component layout data. Cargo oil tank structural data includes the tank's geometry, bilge structure, pump inlet location, bilge flow channel location, main cargo oil inlet location, bulkhead location, and the location of each temperature monitoring point. Heating component layout data includes the length, installation height, longitudinal position, lateral position, and structural correlation factor between the heat exchange components of each heating zone and the critical pumping area.

[0048] The topology identification module calculates the length of heat exchange components currently covered by cargo oil in each heating zone based on the cargo oil level, ship trim angle, and ship heel angle from the ship's attitude data. The module also determines a heat exchange effectiveness correction factor for each heating zone by considering condensate status, thermal response status, and historical effective heat exchange status. When steam is introduced into a heating zone and the condensate outlet temperature, condensate flow rate, or thermal response coefficient falls below a preset thermal response threshold, the topology identification module reduces the heat exchange effectiveness correction factor for that heating zone. The preset thermal response threshold is determined based on historical effective heating data for similar cargo oil or initial identification data after loading.

[0049] The heating control module is used for system calculation, judgment, and control output. It includes a heat calculation unit, a response identification unit, a margin calculation unit, a cause classification unit, and an output control unit. The heating control module can be implemented using a programmable logic controller (PLC), a marine automation controller, an industrial computer, or a control device with equivalent computation and control output capabilities. The heating control module connects to the independent regulating valves of the heating zone module, the low-flow drive unit of the heat flux verification module, the isolation valve group, and the bypass valve group via a control interface.

[0050] The heat calculation unit calculates the effective heat input for each heating zone based on the operating status of the heating zone output by the parameter acquisition module. The response identification unit calculates the thermal response coefficient based on the temperature change of the key pumping area before and after the heat pulse or substitution perturbation, and uses the thermal response coefficient as the thermal response result. The heating control module obtains the verification equivalent pressure loss based on the verification channel data and unloading demand data, and determines the heat flow improvement coefficient based on the change of the verification equivalent pressure loss before and after thermal response identification, using the heat flow improvement coefficient as the heat flow improvement result. The margin calculation unit calculates the pumping margin of the key pumping area based on the verification equivalent pressure loss, target unloading flow rate, pipeline pressure loss, and static pressure correction term. The cause classification unit determines the anomaly cause type based on the effective heat input, thermal response result, heat flow improvement result, verification equivalent pressure loss, effective immersion factor, condensate state, and pipeline inlet state. The output control unit outputs the valve opening degree or equivalent heating power command for each heating zone based on the heating demand weight and anomaly suppression term.

[0051] See attached document Figure 2 This invention provides an adaptive heating control method for oil tanker cargo oil changing operating conditions. The method is based on the operation of a heating zoning module, a parameter acquisition module, a heat flow verification module, a topology identification module, and a heating control module.

[0052] The method includes steps S100 to S500. Step S100 involves collecting variable operating condition data from the cargo oil tank and calculating the effective heat input for each heating zone, executed through the parameter acquisition module and the heating control module. Step S200 involves performing thermal response identification and obtaining the verification equivalent pressure loss under safe access conditions, executed through the heating control module and the heat flow verification module. Step S300 involves reconstructing the current effective heating topology based on the liquid level attitude and response results, executed through the topology identification module and the heating control module. Step S400 involves calculating the pumping margin of key pumping areas and generating zoned heating requirements, executed through the heating control module. Step S500 involves outputting control commands for each heating zone based on the anomaly cause classification results, executed through the heating control module.

[0053] See attached document Figure 3 Step S100 involves collecting variable operating condition data from the cargo oil tanks and calculating the effective heat input for each heating zone. This is executed through the parameter acquisition module and the heating control module. It includes the following sub-steps: Sub-step S101: Collect the operating status of the heating zone and determine the validity of the heating status data.

[0054] The parameter acquisition module collects the valve opening degree, steam inlet pressure, steam inlet temperature, condensate outlet temperature, condensate flow rate, and drainage status of each heating zone, and forms the operating status of the heating zone. For cargo oil tanks heated by heat transfer oil, the parameter acquisition module collects the inlet pressure, inlet temperature, outlet temperature, and circulation flow rate of the heat transfer medium, and forms the operating status of the heating zone.

[0055] The parameter acquisition module adds sampling time to the heating zone's operating status. This sampling time is used to establish a data correspondence within the same control cycle with data on the cargo oil status in key pumping areas, ship attitude data, unloading demand data, and verification channel data. The heating zone's operating status is transmitted to the heat calculation unit of the heating control module.

[0056] The parameter acquisition module assesses the effectiveness of the heating zone's operating status. If the difference between the valve feedback signal and the valve control command exceeds a preset valve position deviation threshold, the module marks the heating zone as having an abnormal valve response. If the condensate flow rate is less than the preset lower limit and the steam inlet pressure is higher than the preset lower limit, the module marks the heating zone as having a drainage abnormality. The preset valve position deviation threshold is determined based on the valve positioner's allowable deviation; the preset lower limit of condensate flow rate is determined based on the design heat exchange load of the heating zone; and the preset lower limit of steam pressure is determined based on the minimum steam supply pressure of the steam heating system.

[0057] Sub-step S102: Collect data on the status of cargo oil and the attitude of the ship in the key pumping area.

[0058] The parameter acquisition module collects the temperatures in the area adjacent to the pump suction inlet, the bilge flow channel area, and the cargo oil main inlet area, thus establishing the cargo oil status of key pumping areas. At least one representative temperature detection point is set for each key pumping area. When multiple temperature detection points are set for the same area, the parameter acquisition module determines the representative temperature of that key pumping area according to preset value selection rules. These preset rules include using the lowest detected temperature, using a weighted average temperature, or using the temperature detected closer to the pump suction inlet.

[0059] The parameter acquisition module collects cargo oil level, ship trim angle, and ship heel angle, and generates ship attitude data. The cargo oil level is used to determine the length of the heating element covered by cargo oil. The ship trim and heel angles are used to correct the position of the cargo oil level relative to the heating element. The ship attitude data is then transmitted to the topology identification module.

[0060] The parameter acquisition module collects estimated unloading time, target unloading flow rate, allowable suction conditions of the unloading pump, target unloading temperature, and target unloading viscosity, and generates unloading demand data. The estimated unloading time is used to determine the control priority of critical pumping areas. The target unloading flow rate is used to calculate the pressure loss in critical pumping areas under unloading conditions. The allowable suction conditions of the unloading pump are used to determine the allowable pressure loss boundary of critical pumping areas.

[0061] Sub-step S103: Calculate the effective heat input of the heating zone based on the parameters of the steam side and the condensate side.

[0062] The heat calculation unit of the heating control module calculates the effective heat input for each heating zone based on the steam inlet enthalpy, condensate outlet enthalpy, condensate mass flow rate, and effective heat supply correction factor. Effective heat input characterizes the heat transferred from the heating zone to the cargo oil side during the current control cycle.

[0063] The effective heat input formula is as follows: ; in, For the first Key pumping areas at time The corresponding verification equivalent pressure loss represents the pressure loss of the cargo oil in the key pumping area, calculated from the low flow verification results under the target unloading equivalent demand flow rate, in kPa. For the first Key pumping areas at time The corresponding verification channel inlet pressure represents the pressure of the low-flow verification cargo oil before it enters the measuring pipe section, and the unit is kPa. For the first Key pumping areas at time The corresponding verification channel outlet pressure represents the pressure after the low-flow verification cargo oil flows out of the measuring pipe section, and the unit is kPa. For the first The target unloading equivalent flow rate for each key pumping area represents the corresponding volumetric flow rate of cargo oil required for that key pumping area under the target unloading condition, expressed in m³. 3 / h; For the first Key pumping areas at time The corresponding verification channel low flow rate represents the volumetric flow rate of cargo oil through the pipeline section measured via the verification channel, in cubic meters per second (m³). 3 / h; To verify the channel flow index, which represents the relationship between channel pressure difference and flow rate, a value of 1 to 2 is used.

[0064] In this formula for verifying equivalent pressure loss, the ratio of the target unloading equivalent demand flow rate to the low flow rate of the verification channel is the ratio of the same type of flow rate. After the ratio is corrected by the flow rate index of the verification channel, it is still a numerical coefficient. The unit of the verification equivalent pressure loss remains kPa.

[0065] When the verified equivalent pressure loss exceeds the preset pressure loss threshold, the heating control module determines that the oil in the key pumping area has an abnormal pressure loss after being converted to the target unloading equivalent flow rate. The preset pressure loss threshold is determined based on the target unloading viscosity of the oil, the verification channel structure parameters, and the target unloading flow rate.

[0066] Sub-step S204: Calculate the heat flow improvement result based on the verified equivalent pressure loss change.

[0067] The heating control module compares the changes in equivalent pressure loss before and after thermal response identification, calculates the heat flow improvement coefficient based on the effective heat input to the target heating zone, and uses this coefficient as the heat flow improvement result. The heat flow improvement coefficient represents the effect of the heat input to the target heating zone on reducing pressure loss in the critical pumping area.

[0068] The formula for the heat flux improvement factor is as follows: ; in, For the first The heating zone for the first The heat flow improvement coefficient for a key pumping region represents the contribution of a unit effective heat input in that heating zone to the reduction of the equivalent pressure loss in the key pumping region, expressed in kPa / kJ.

[0069] When the thermal response coefficient is not lower than the preset thermal response threshold and the heat flow improvement coefficient is lower than the preset heat flow improvement threshold, the heating control module determines that the heating zone generates a temperature response to the critical pumping area, but does not correspondingly reduce the verified equivalent pressure loss of the critical pumping area. The preset heat flow improvement threshold is determined based on historical effective heating data of similar cargo oil or initial identification data after loading.

[0070] See attached document Figure 5 Step S300: Reconstruct the current effective heating topology based on the liquid level attitude and response results. This is executed through the topology identification module and the heating control module. It includes the following sub-steps: Sub-step S301: Calculate the effective immersion state of the heating zone based on the liquid level and coil arrangement.

[0071] The topology identification module calculates the length of the heat exchange components currently covered by cargo oil in each heating zone based on the ship's attitude data, including cargo oil level, ship's trim angle, ship's heel angle, and heating zone layout data. This heat exchange component length represents the portion of the heating zone that can directly exchange heat with the cargo oil.

[0072] The effective immersion factor formula is as follows: ; in, For the first Each heating zone at time The effective immersion factor represents the degree to which the heating zone can effectively exchange heat with the cargo oil under the current liquid level and ship attitude, and its value ranges from 0 to 1. For the first Each heating zone at time The length currently effectively submerged by cargo oil represents the length of heating components that participate in effective heat exchange under the current cargo oil level, ship trim, and ship list conditions, and is expressed in meters (m). For the first The total heat exchange length of a heating zone represents the total length of all heat exchangeable components in that heating zone, and is expressed in meters (m). For the first Each heating zone at time The heat transfer effectiveness correction factor represents the correction of the heat transfer effectiveness of the heating zone based on the condensate state, thermal response state, and historical effective heat transfer state, and its value ranges from 0 to 1.

[0073] When the effective immersion factor is lower than the preset effective immersion threshold, the topology identification module marks the corresponding heating zone as insufficiently immersed. This status is transmitted to the heating control module and used to generate anomaly suppression terms.

[0074] Sub-step S302 involves normalizing the thermal response results and the heat flow improvement results.

[0075] The topology identification module normalizes the thermal response coefficient, which is a result of thermal response, and the thermal flux improvement coefficient, which is a result of thermal flux improvement. The normalization process is used to convert response results of different units into relative response quantities that can participate in the same control allocation calculation, and to remove negative responses or negative improvements from the calculation of effective heat transfer relationships.

[0076] The normalized thermal response coefficients are as follows: ; The normalized heat flux improvement factor is as follows: ; in, For the first The heating zone for the first Key pumping areas at time The normalized thermal response coefficient, which represents the relative heating capacity of the heating zone to the critical pumping zone, has a value ranging from 0 to 1. For the first The heating zone for the first Key pumping areas at time The normalized heat flux improvement coefficient, which represents the relative contribution of the heating zone to the reduction of the equivalent pressure loss in the key pumping area, has a value of 0 to 1. For the first The heating zone for the first Key pumping areas at time The thermal response coefficient represents the ability of the heating zone to generate a temperature response to the key pumping area per unit effective heat input, and its unit is ℃ / kJ; For the first The heating zone for the first Key pumping areas at time The heat flow improvement coefficient represents the contribution of a unit effective heat input in the heating zone to the reduction of the equivalent pressure loss in the critical pumping area, and is expressed in kPa / kJ. For the first The heating zone for the first Key pumping areas at time The positive part of the thermal response coefficient represents the thermal response result after retaining only the positive heating response, and the unit is ℃ / kJ; For the first The heating zone for the first Key pumping areas at time The positive value of the heat flow improvement coefficient represents the heat flow improvement result after retaining only the verification equivalent pressure loss reduction, and the unit is kPa / kJ; For the first The reference thermal response coefficient of a key pumping area represents the reference temperature rise capacity of the key pumping area under historical effective operating conditions, sea trial operating conditions, or initial identification operating conditions, and the unit is ℃ / kJ. For the first The baseline heat flux improvement coefficient for each key pumping region represents the reference verification equivalent pressure loss reduction capability of that key pumping region under historical effective operating conditions, sea trial operating conditions, or initial identification operating conditions, and is expressed in kPa / kJ. This is the thermal response correction amount, which represents a positive number used to prevent the denominator from being zero when the reference thermal response coefficient is zero, and its unit is ℃ / kJ; This is the heat flux improvement correction amount, which represents a positive number used to prevent the denominator from being zero when the reference heat flux improvement factor is zero, and its unit is kPa / kJ; This is the smaller function, which means taking the smaller value between the two values ​​inside the parentheses; Let be a positive part function, which represents when Time to take ,when Take 0 at that time.

[0077] The baseline thermal response coefficient and baseline heat flux improvement coefficient are stored by the topology identification module. Both are derived from recorded data from the initial identification of the same cargo tank after sea trials or loading, or from historical effective heating processes. They maintain a corresponding relationship within the same cargo tank and the same critical pumping area.

[0078] Sub-step S303 generates the effective heat transfer relationship between the heating zone and the key pumping zone.

[0079] The topology identification module generates the effective heat transfer relationship between the heating zone and the critical pumping zone based on the effective immersion factor, structural correlation factor, normalized thermal response coefficient, and normalized heat flux improvement coefficient. This effective heat transfer relationship is used to determine which heating zone is suitable for supplementing the heating of which critical pumping zone under the current operating conditions.

[0080] The effective heat transfer relationship is as follows: ; in, For the first The heating zone for the first Key pumping areas at time The effective heat transfer relationship represents the overall effectiveness of the heating zone in improving the heating and flow conditions of the key pumping area under the current operating conditions, and its value ranges from 0 to 1. For the first The heating zone and the first The structural correlation factor between key pumping areas represents the degree of heat transfer correlation between them, determined by spatial location, bilge structure, and piping arrangement, and has a value ranging from 0 to 1.

[0081] When the effective heat transfer relationship is lower than a preset effective transfer threshold, the topology identification module marks the relationship between the corresponding heating zone and the key pumping area as a low effective relationship. The preset effective transfer threshold is determined based on the cargo tank structure, heating zone layout, and historical effective heating results. When generating heating demand weights, the heating control module reduces the allocation priority of heating zones corresponding to low effective relationships.

[0082] See attached document Figure 6 Step S400: Calculate the pumping margin of the key pumping area and generate zoned heating requirements. This is executed through the heating control module. It includes the following sub-steps: Sub-step S401: Calculate the pumping margin based on the verified equivalent pressure loss and unloading requirements.

[0083] The heating control module calculates the pumping margin for the critical pumping zone based on the verified equivalent pressure loss, pipeline pressure loss, static pressure correction term, and allowable pressure loss boundary. The pumping margin represents the pressure margin required to meet the unloading pumping conditions in the critical pumping zone.

[0084] The pumping margin formula is as follows: ; in, For the first Key pumping areas at time The pumping margin represents the pressure clearance of the critical pumping area from meeting the unloading pumping conditions, and is expressed in kPa. For the first Key pumping areas at time The allowable pressure loss boundary represents the upper limit of pressure loss that the unloading pump or cargo oil system is allowed to consume in this critical pumping area, in kPa. For the first Key pumping areas at time The pipeline pressure loss represents the pressure loss caused by the main oil inlet, local valves, or related pipe sections, and is expressed in kPa. For the first Key pumping areas at time The static pressure correction term represents the additional pressure loss caused by cargo oil level, ship trim, and ship list, expressed in kPa. When cargo oil level, ship trim, and ship list generate favorable static pressure effects... Take 0.

[0085] in, The verified equivalent pressure loss obtained in step S203, in kPa, can be added or subtracted in the same unit as the allowable pressure loss boundary, pipeline pressure loss, and static pressure correction term.

[0086] When the pumping margin is lower than the target pumping margin, the heating control module determines that there is a heating requirement or pipeline preheating requirement for that critical pumping area. When the pumping margin is not lower than the target pumping margin, the heating control module does not generate any new heating requirement for that critical pumping area.

[0087] Sub-step S402: Determine the demand gap in key areas based on the target pumping margin.

[0088] The heating control module compares the pumping margin of key pumping areas with the target pumping margin. The target pumping margin is determined based on the allowable suction conditions of the unloading pumps, the target unloading flow rate of the cargo oil, and the pressure limits of the ship's cargo oil system. The target pumping margin can be set to different values ​​during the navigation phase, the unloading preparation phase, and the unloading phase.

[0089] When the expected unloading time is earlier than anticipated, the heating control module increases the demand weighting of the area near the pump suction inlet and the cargo oil main inlet area. When the expected unloading time is later than anticipated, the heating control module decreases the demand weighting of the central insulation heating zone and the heating zone near the bulkhead, while maintaining the target pumping margin requirements for critical pumping areas.

[0090] Demand gaps in critical areas only arise when pumping margins fall below the target pumping margin. Critical pumping areas where pumping margins meet the target pumping margin are not included in the positive allocation of additional heating demand.

[0091] Sub-step S403: Generate zone heating demand weights based on effective heat transfer relationships.

[0092] The heating control module generates heating demand weights for each heating zone based on the demand gaps and effective heat transfer relationships in each key pumping area. These heating demand weights represent the degree of heat allocation required by each heating zone within the current control cycle.

[0093] The formula for weighting heating demand is as follows: ; in, For the first Each heating zone at time The heating demand weight represents the degree of heat allocation required by the heating zone during the current control cycle, expressed in kPa. For the first The demand weight of each key pumping area represents the control priority of that key pumping area in the current unloading phase, and the value ranges from 0 to 1. For the first Key pumping areas at time The target pumping margin represents the pressure margin that the system requires to be maintained in this critical pumping area, expressed in kPa. For the first Key pumping areas at time The positive value of the pumping margin gap represents the effective demand generated only when the target pumping margin is not met, and is expressed in kPa. After the heating demand weights are calculated, the heating control module transmits the heating demand weights of each heating zone to the cause classification unit. The cause classification unit, in conjunction with the abnormal state, limits or maintains the heating demand weights.

[0094] See attached document Figure 7 Step S500: Based on the anomaly cause classification results, output control commands for each heating zone. These commands are executed by the heating control module. This includes the following sub-steps: Sub-step S501: Determine the type of abnormality based on heat input, response results, and pipeline status.

[0095] The heating control module performs cause classification based on effective heat input, thermal response coefficient, heat flux improvement coefficient, effective immersion factor, verified equivalent pressure loss, condensate state, and pipeline inlet state. Cause classification is used to determine whether the system should perform steam load adjustment, heating zone switching, pump suction inlet insulation, cargo oil pipeline inlet preheating, low-flow closed-loop circulation, or anomaly suppression within the current control cycle.

[0096] When the effective heat input is lower than the preset effective heat input threshold and the temperature change in the key pumping area is lower than the preset temperature change threshold, the heating control module determines it as insufficient heating. The preset effective heat input threshold is determined based on the designed heat exchange load of the heating zone. The preset temperature change threshold is determined based on the resolution of the cargo oil temperature detector and the control cycle length.

[0097] When the effective heat input is not lower than the preset effective heat input threshold and the thermal response coefficient is lower than the preset thermal response threshold, the heating control module determines it to be a heat exchange failure type. When the thermal response coefficient is not lower than the preset thermal response threshold and the heat flow improvement coefficient is lower than the preset heat flow improvement threshold, the heating control module determines it to be a thermal response effective but pumping improvement insufficient type. When the pipeline pressure loss in the cargo oil main inlet area is higher than the preset pipeline pressure loss threshold, the heating control module determines it to be a pipeline inlet restriction type. When the effective immersion factor is lower than the preset effective immersion threshold, the heating control module determines it to be an effective immersion insufficient type.

[0098] Sub-step S502: Generate corresponding heating zone abnormality suppression items based on the type of abnormality cause.

[0099] The heating control module generates anomaly suppression items based on the cause classification results. These anomaly suppression items are used to limit heating zones where further heat output is not suitable, and to enable the heating control module to select heating output targets from other heating zones where the effective heat transfer relationship meets the requirements.

[0100] For heat exchange failure type, the heating control module increases the anomaly suppression term of the corresponding heating zone and reduces the output increment of that heating zone in the next control cycle. For insufficient effective immersion type, the heating control module increases the anomaly suppression term of the corresponding heating zone and prioritizes heating zones where the current effective immersion factor is not lower than the preset effective immersion threshold. For effective thermal response but insufficient pumping improvement type, the heating control module does not continue to increase the output of that heating zone separately, but instead performs pump inlet insulation, cargo oil pipeline inlet preheating, or low-flow closed-loop circulation.

[0101] For verification channel anomalies, the heating control module isolates the heat flux verification module and enters degraded control. Degraded control uses effective heat input, representative temperature of the key pumping area, effective immersion factor, and steam-side status to generate the heating zone control output. Degraded control does not use the verification equivalent pressure loss to calculate the improved heat flux.

[0102] Sub-step S503 generates control output based on demand weights and anomaly suppression terms.

[0103] The heating control module outputs control commands for the next control cycle for each heating zone based on heating demand weights, control gain, anomaly suppression coefficients, and anomaly suppression terms. These control commands include steam regulating valve opening degree, heat transfer medium regulating valve opening degree, or equivalent heating power command.

[0104] The control output formula is as follows: ; in, For the first The control output of each heating zone in the next control cycle represents the valve opening degree or equivalent heating power command for that heating zone in the next control cycle, expressed in % (%). The control cycle length represents the time interval between two consecutive control outputs, measured in seconds. For the first The control output of each heating zone in the current control cycle represents the valve opening degree or equivalent heating power command of that heating zone in the current control cycle, expressed in % (%). For the first The control gain of each heating zone represents the proportion of the heating demand weight converted into the control output increment, in % / kPa; For the first The abnormal suppression coefficient of each heating zone represents the reduction strength of the abnormal suppression term on the control output, and its value ranges from 0 to 1; For the first Each heating zone at time The abnormal inhibition term represents the restriction on continued heating of the heating zone caused by heat transfer failure, insufficient effective immersion, hydrophobic abnormalities, or verification anomalies, expressed in % (%). The control output limiting function represents a function that limits the control output to the allowable valve opening or allowable heating power range, with an output range of 0% to 100%.

[0105] After the heating control module outputs control commands, the parameter acquisition module continues to collect data on the operating status of the heating zone, the status of cargo oil in the key pumping area, ship attitude data, and verification channel data in the next control cycle. These steps are executed cyclically until cargo oil unloading is completed or the system exits the adaptive heating control state.

[0106] Specific application examples: See attached document Figure 8 The horizontal axis represents time in minutes, and the vertical axis represents pumping margin in kPa. Figure 8 This includes curves for the area adjacent to the pump suction inlet, the bilge flow channel area, the cargo oil main inlet area, and the target pumping margin curve. The curve for the area adjacent to the pump suction inlet is represented by a solid black line and a circle, the curve for the bilge flow channel area is represented by a dashed black line and a square, the curve for the cargo oil main inlet area is represented by a dotted line and a diamond, and the target pumping margin curve is represented by a dashed black line and a triangle. Figure 8 The target pumping margin is maintained at 20 kPa, and the background grid lines are dashed lines.

[0107] In this embodiment, a cargo oil tank of a certain oil tanker is equipped with five heating zones: a bilge pump suction inlet heating zone, a bilge far-end heating zone, a bulkhead adjacent heating zone, a central insulation heating zone, and a cargo oil pipeline inlet preheating zone. Three key pumping areas are designated: the area adjacent to the pump suction inlet, the bilge flow channel area, and the cargo oil main inlet area. Figure 8 During the control period, the pumping margin in the area near the pump suction port increased from approximately 6.5 kPa initially to over 20 kPa; the pumping margin in the bilge flow channel area increased from approximately 5.0 kPa initially to approximately 17 kPa; the pumping margin in the cargo oil main inlet area increased from approximately 4.7 kPa initially to approximately 14 kPa; and the target pumping margin remained at 20 kPa.

[0108] During the unloading preparation phase, the heating control module selects the bilge pump suction inlet heating zone as the target heating zone. The value is: For 0s, For 900s, The value is 120,000 kJ, and the pressure is in the vicinity of the pump suction port. The temperature was 47.2℃, near the pump suction port. The temperature is 48.0℃. Substituting the above parameters into... The corresponding thermal response coefficient formula is used to calculate the effect of the bilge pump suction inlet heating zone on the area adjacent to the pump suction inlet. It is 6.67×10 -6℃ / kJ. This calculation result indicates that the heating zone at the bilge pump inlet creates a recordable temperature response to the area adjacent to the pump inlet.

[0109] During the same identification process, the heat flow verification module measured the area near the pump inlet at the start of the identification process. The Pa is 138 kPa. The pressure is 98 kPa. 12m 3 / h, 18m 3 / h, Take 1. Substitute the above parameters into... The corresponding verification equivalent pressure loss formula is used to calculate the pressure loss in the region adjacent to the pump inlet at the start of identification. The pressure is 60 kPa. At the end of the identification process, the area near the pump suction port... The pressure is 130 kPa. The pressure is 98 kPa. 12m 3 / h, 18m 3 / h, Taking 1 and substituting it into the same formula, we get... The pressure is 48 kPa. , and Substitution The corresponding heat flow improvement coefficient formula is used to calculate the effect of the bilge pump suction inlet heating zone on the area adjacent to the pump suction inlet. 1.00×10 -4 kPa / kJ. This calculation result indicates that the heat input to the bilge pump inlet heating zone reduces the verified equivalent pressure loss in the area adjacent to the pump inlet under the target unloading equivalent demand flow rate.

[0110] The topology identification module calculates the heating zone of the bilge pump suction port based on the cargo oil level, the ship's trim angle, and the ship's list angle. It is 82m. It is 90m. The value is 0.90. Substitute the above parameters into... The corresponding effective immersion factor formula was used to calculate the heating zone of the bilge pump suction port. The value is 0.82. The topology identification module uses the region near the pump inlet. 8.00×10 -6 ℃ / kJ, 1.10×10 -4 kPa / kJ, It is 0.95, and combined with the above , The calculation yields the heating zone of the bilge pump suction port relative to the area adjacent to the pump suction port. The value is 0.59. This calculation result is used to determine the control priority of the bilge pump suction inlet heating zone for supplementing heating of the area adjacent to the pump suction inlet during the current control cycle.

[0111] The heating control module uses the area adjacent to the pump suction port during the pumping margin calculation. The pressure is 80 kPa, and the pressure at the end of the identification process is used. The pressure is 48 kPa. The pressure is 12 kPa. The value is 5 kPa. Substitute the above parameters into... The corresponding pumping margin formula is used to calculate the pump suction port area. The target pumping margin is 15 kPa. The pressure is 20 kPa, therefore there is a 5 kPa pumping margin gap in the area near the pump inlet. This calculation result enables the heating control module to generate heating requirements for the area near the pump inlet.

[0112] During this control cycle, the area adjacent to the pump suction port Select 1. The heating control module will... For 20kPa, For 15kPa, Substitute 0.59 The corresponding heating demand weighting calculation process yields the heating zone of the bilge pump suction inlet. Approximately 3.0 kPa. Current control output. It is 42%. is 3% / kPa, 2%, The value is 0.5. Substitute the above parameters into... The corresponding control output formula yields the heating zone of the bilge pump suction port for the next control cycle. Approximately 50%. Based on this, the heating control module increases the valve opening in the heating zone of the bilge pump suction port while maintaining the output of other heating zones with low effective heat transfer relationships without increasing.

[0113] Combination Figure 8 As shown in the curve, at approximately 120 minutes of control time, the pumping margin in the area near the pump inlet reaches near the target pumping margin. As the control time continues to increase, the pumping margin in the area near the pump inlet remains near or above the target pumping margin. The pumping margin in the bilge flow channel area and the cargo oil main inlet area gradually increases with increasing control time, but is not forcibly increased to the same level as the area near the pump inlet. The corresponding control action is as follows: the heating control module prioritizes increasing the output of the bilge pump inlet heating zone that has an effective heat transfer relationship with the area near the pump inlet, and maintains the supplementary heating demand of the corresponding heating zone based on the pumping margin gap in the bilge flow channel area and the cargo oil main inlet area.

[0114] Experimental verification and effect comparison section: See attached document Figure 9 The horizontal axis represents time in minutes, and the vertical axis represents pumping margin in kPa. Figure 9 This includes curves representing the region adjacent to the pump suction port of a conventional control pump, curves representing the region adjacent to the main cargo oil inlet of a conventional control pump, curves representing the region adjacent to the pump suction port of the present invention, curves representing the region adjacent to the main cargo oil inlet of the present invention, and a target pumping margin curve. The curve representing the region adjacent to the pump suction port of a conventional control pump is represented by a solid black line and circular markers; the curve representing the region adjacent to the main cargo oil inlet of a conventional control pump is represented by a dashed black line and square markers; the curve representing the region adjacent to the pump suction port of the present invention is represented by a dotted black line and diamond markers; the curve representing the region adjacent to the main cargo oil inlet of the present invention is represented by a dashed black line and triangle markers; and the target pumping margin curve is represented by a solid black line and cross markers. Figure 9 The target pumping margin is maintained at 20 kPa, and the background grid lines are dashed lines.

[0115] In this embodiment, the test object is a simulated cargo oil tank on a ship test platform. This simulated cargo oil tank is equipped with 5 heating zones and 3 key pumping areas. The comparative control method is a traditional temperature setting control method, while the experimental control method is the adaptive heating control method for oil tanker cargo oil under varying operating conditions of this invention.

[0116] Under the same initial cargo oil conditions, traditional temperature setting and control methods use the average temperature inside the tank as the control target, and each heating zone uniformly increases or decreases its heating output based on the deviation of the average temperature. The control method of this invention generates heating demand weights for each heating zone based on the pumping margin gap of the area adjacent to the pump suction port, the bilge flow channel area, and the cargo oil main inlet area, as well as the effective heat transfer relationship.

[0117] Figure 9 In traditional methods, the pumping margin near the pump suction inlet gradually increases from an initial approximately 4.8 kPa to approximately 15.5 kPa, and the pumping margin near the cargo oil main inlet gradually increases from an initial approximately 4.3 kPa to approximately 12.2 kPa. In this invention, the pumping margin near the pump suction inlet gradually increases from an initial approximately 6.3 kPa to over 20 kPa, and approaches or exceeds the target pumping margin after approximately 80 minutes. In this invention, the pumping margin near the cargo oil main inlet gradually increases from an initial approximately 5.5 kPa to approximately 18.6 kPa. The target pumping margin curve remains at 20 kPa.

[0118] Within one test cycle, the parameters were set as follows: cumulative steam consumption of the traditional temperature setting control method was 18.6t; the verified equivalent pressure loss near the pump inlet at the end of unloading preparation was 57kPa; the corresponding pipeline pressure loss near the pump inlet was 2.5kPa; the corresponding static pressure correction term near the pump inlet was 5kPa; and the allowable pressure loss boundary was 80kPa. Substituting the above parameters into... The corresponding pumping margin formula yields a pumping margin of 15.5 kPa at the end of unloading preparation in the vicinity of the pump inlet under the traditional temperature setting control method. This calculation result is consistent with... Figure 9 The end position of the curve in the vicinity of the suction port of the traditional Chinese control pump is consistent.

[0119] The parameter values ​​for the control method of this invention are as follows: the verified equivalent pressure loss in the area near the pump inlet at the end of unloading preparation is 39 kPa, the corresponding pipeline pressure loss in the area near the pump inlet is 14.4 kPa, the corresponding static pressure correction term in the area near the pump inlet is 5 kPa, and the allowable pressure loss boundary is 80 kPa. Substituting the above parameters into... The corresponding pumping margin formula yields a pumping margin of 21.6 kPa at the end of unloading preparation in the area near the pump inlet under the control method of this invention. This calculation result is consistent with... Figure 9 In this invention, the end position of the curve in the region adjacent to the pump suction port is consistent.

[0120] Within the same test cycle, under the traditional temperature control method, the pressure loss at the inlet of the main cargo oil pipe was 16.5 kPa, and the estimated amount of residual cargo oil in the bilge after unloading was 4.7 m³. 3 Under the control method of this invention, the pipeline pressure loss at the main cargo oil inlet is 12.4 kPa, and the estimated amount of residual cargo oil in the bilge after unloading is 3.1 m³. 3 The above data corresponds to Figure 9 The results of the curve changes. Figure 9 The results show that, within the same control time, the pumping margin in the area adjacent to the pump inlet under the control method of the present invention enters the target range earlier than that under the traditional temperature setting control method; the pumping margin in the inlet area of ​​the cargo oil main pipe under the control method of the present invention is higher than that under the traditional temperature setting control method.

[0121] according to Figure 9 As shown, the heating control module, under the control method of this invention, according to... and The resulting pumping margin gap, and The established effective heat transfer relationship prioritizes adjusting the control output of the bilge pump suction inlet heating zone and the cargo oil pipeline inlet preheating zone. Traditional temperature setting control methods primarily target the average temperature inside the tank, failing to differentiate the control of the heating zone based on the pumping margin gap in key pumping areas.

[0122] The specific application examples and experimental verification data described above illustrate the operation of the system and method of the present invention. The number of heating zones, the number of key pumping areas, the control cycle, the control gain, the threshold, and the demand weight can be set according to the cargo oil tank structure, the type of cargo oil, the ship's heating medium, and the unloading conditions. During the setting process, the heating control module maintains a one-to-one correspondence between the heating zone number, the key pumping area number, the source of the detection data, and the control output object.

Claims

1. An adaptive heating control system for cargo oil tankers under varying operating conditions, characterized in that, include: The heating zoning module is used to divide the heating components in the cargo oil tank into multiple independently adjustable heating zones and establish a preset positional relationship between each heating zone and the key pumping area. The parameter acquisition module is used to collect and time-mark the operating status of the heating zone, the status of cargo oil in key pumping areas, ship attitude data, unloading demand data, and verification channel data. The thermal flow verification module is used to establish a controlled low-flow verification process under abnormal unloading conditions. The topology identification module is used to determine the effective immersion state and effective heat transfer relationship based on the preset positional relationship, the ship attitude data, thermal response results, and heat flow improvement results. The heating control module is used to calculate the effective heat input based on the operating status of the heating zone, obtain the thermal response result based on the effective heat input and the cargo oil status of the key pumping area, obtain the verification equivalent pressure loss based on the verification channel data and the unloading demand data, and determine the pumping margin, heating demand weight, and abnormal cause type based on the effective heat transfer relationship and the verification equivalent pressure loss, and output control commands.

2. The tanker cargo oil variable operating condition adaptive heating control system according to claim 1, characterized in that, The heating partitioning module is used to divide heating zones and establish preset positional relationships, specifically including: The heating components are divided into the bilge pump suction port heating zone, the bilge far end heating zone, the bulkhead adjacent heating zone, the central insulation heating zone, and the cargo oil pipeline inlet preheating zone. Each of the heating zones is connected to an independent regulating valve, which is used to change the steam flow rate, heat transfer medium flow rate, or equivalent heating power of the corresponding heating zone; The preset positional relationships include the height position, longitudinal position, lateral position, total length of heat exchange components, distance relationship with the area adjacent to the pump inlet and the bilge flow channel area of ​​each heating zone, and pipeline relationship with the cargo oil main inlet area.

3. The tanker cargo oil variable operating condition adaptive heating control system according to claim 1, characterized in that, The parameter acquisition module is used to acquire data and perform time stamping, specifically including: Collect data on valve opening, steam inlet pressure, steam inlet temperature, condensate outlet temperature, condensate flow rate, and drainage status for each heating zone; Collect the following data: temperature in the area near the pump suction inlet, temperature in the bilge flow channel area, temperature in the cargo oil main inlet area, cargo oil level, ship trim angle, ship heel angle, estimated unloading time, target unloading flow rate, allowable suction conditions of the unloading pump, target unloading temperature, and target unloading viscosity. The inlet pressure, outlet pressure, inlet temperature, outlet temperature, and verification flow rate of the heat flow verification module are collected. When the detected value exceeds the sensor's range, the signal is interrupted, or the continuous sampling value does not meet the preset range of change, the corresponding data will be marked as invalid data.

4. The tanker cargo oil variable operating condition adaptive heating control system according to claim 1, characterized in that, The heat flow verification module is used to form the controlled low flow verification process, specifically including: It is equipped with a low-flow drive unit, a cleanable measuring pipe section, a differential pressure detection unit, a temperature detection unit, an isolation valve group, a bypass valve group, a heat tracing unit, a drain port, and a flushing port; Connect the inlet of the heat flow verification module to the area adjacent to the pump suction port, the bilge flow channel area, or the cargo oil main inlet area, and make the outlet of the heat flow verification module return to the same cargo oil tank or the same cargo oil circulation loop. When the pressure difference between the inlet and outlet of the verification channel exceeds a preset safety differential pressure threshold, or the verification flow rate is lower than a preset minimum verification flow rate threshold, or the verification channel temperature is lower than a preset minimum channel temperature threshold, the heating control module stops the operation of the heat flow verification module and controls the isolation valve group to close.

5. The tanker cargo oil adaptive heating control system according to claim 1, characterized in that, The heating control module is used to calculate the effective heat input, specifically including: The effective heat input of each heating zone is obtained based on the steam inlet enthalpy, condensate outlet enthalpy, condensate mass flow rate, and effective heating correction factor. When using heat transfer oil heating, the effective heat input of each heating zone is obtained based on the inlet temperature of the heat transfer medium, the outlet temperature of the heat transfer medium, the circulation flow rate, and the specific heat capacity of the heat transfer medium. The effective heat input is used to obtain the thermal response result, determine the heat flow improvement result, and determine the type of the abnormality cause.

6. The tanker cargo oil variable operating condition adaptive heating control system according to claim 2, characterized in that, The heating control module is used to obtain the thermal response result, specifically including: Before performing thermal response identification, determine whether the target heating zone meets the thermal pulse access conditions; When the target heating zone meets the thermal pulse access condition, the independent regulating valve of the target heating zone is controlled to change its opening within a preset disturbance range, and a controlled thermal pulse is formed. When the target heating zone does not meet the thermal pulse access condition, the valve fine-tuning response, natural heat dissipation response, or existing low-flow circulation response during the normal heating process are used as alternative perturbation inputs. The thermal response coefficient is obtained based on the temperature change of the key pumping area before and after thermal response identification and the effective heat input, and the thermal response coefficient is used as the thermal response result.

7. The tanker cargo oil variable operating condition adaptive heating control system according to claim 6, characterized in that, The heating control module is used to obtain the verification equivalent pressure loss, specifically including: The controlled low-flow verification process is initiated before and after the thermal response identification. Based on the verification channel inlet pressure, verification channel outlet pressure, verification flow rate, target unloading equivalent demand flow rate, and verification channel flow rate index, the low flow rate verification pressure difference is converted into the verification equivalent pressure loss under the target unloading equivalent demand flow rate. The heat flow improvement result is determined based on the verified equivalent pressure loss change, and the verified equivalent pressure loss is used to determine the pumping margin and the type of anomaly cause.

8. The tanker cargo oil adaptive heating control system according to claim 7, characterized in that, The topology identification module is used to determine the effective immersion state and the effective heat transfer relationship, specifically including: The length of the heat exchange component currently covered by cargo oil in each heating zone is determined based on the preset positional relationship, the cargo oil level in the ship attitude data, the ship's pitch angle, and the ship's roll angle. The heat transfer effectiveness correction factor is determined by combining the condensate state, thermal response state, and historical effective heat transfer state. The effective immersion factor is determined based on the length of the heat exchange component, the total length of the heat exchange component, and the heat exchange effectiveness correction factor. The effective heat transfer relationship is determined based on the effective immersion factor, the structural correlation factor, the normalized thermal response coefficient corresponding to the thermal response result, and the normalized heat flow improvement coefficient corresponding to the heat flow improvement result.

9. The tanker cargo oil variable operating condition adaptive heating control system according to claim 8, characterized in that, The heating control module is used to determine the pumping margin and the heating demand weight, specifically including: The pumping margin of the critical pumping area is calculated based on the verified equivalent pressure loss, pipeline pressure loss, static pressure correction term and allowable pressure loss boundary. A pumping margin gap is formed when the pumping margin is lower than the target pumping margin; The heating demand weights for each heating zone are generated based on the demand weights of key pumping areas, the pumping margin gap, and the effective heat transfer relationship. When the expected unloading time is earlier than scheduled, increase the demand weight of the area near the pump suction port and the cargo oil main inlet area; when the expected unloading time is later than scheduled, decrease the demand weight of the central insulation and heating area and the heating area near the bulkhead.

10. The tanker cargo oil variable operating condition adaptive heating control system according to claim 9, characterized in that, The heating control module is used to determine the type of the abnormality and output the control command, specifically including: The type of abnormal cause is determined based on the effective heat input, the heat response coefficient as the result of the heat response, the heat flow improvement coefficient as the result of the heat flow improvement, the verified equivalent pressure loss, the effective immersion factor obtained from the effective immersion state, the condensate state, and the pipe inlet state. The types of abnormal causes include insufficient heating, heat exchange failure, effective thermal response but insufficient pumping improvement, pipeline inlet restriction, and insufficient effective immersion. Based on the heating demand weight, control gain, anomaly suppression coefficient, and anomaly suppression term, the control command for the next control cycle of each heating zone is output. The control command includes the steam regulating valve opening, the heat transfer medium regulating valve opening, or the equivalent heating power command.

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