A heat dissipation control system of a methanol dual-launch extended-range excavator

Abstract

The application discloses a methanol double-engine range-extended excavator heat dissipation control system, which comprises six independent heat dissipation modules, six water pumps, an intelligent integrated valve and a heat management control unit. The intelligent integrated valve realizes flow distribution and controlled interconnection among cooling circuits through a main proportional valve and a bypass connecting device. The application realizes real-time acquisition of multi-source signals and dynamic adjustment of control parameters. The multi-channel feedback arbitration and feedforward compensation composite control is adopted for the motor and electric control area, and the independent linear control is executed for the engine area. The intelligent valve realizes on-demand flow distribution and cross-area redundant scheduling, and realizes closed-loop monitoring and strategy upgrading. The application solves the problem of collaborative heat dissipation of the double-engine range-extended excavator under the condition of multiple heat sources and high load, and realizes precise temperature control, energy saving and high reliability.

Description

Technical Field

[0001] This invention relates to the field of excavator heat dissipation technology, specifically to a heat dissipation control system for a methanol dual-engine range extender excavator. Background Technology

[0002] With the deepening application of new energy technologies in the construction machinery field, large excavators using dual methanol engine range-extended power systems have become an important development direction for heavy-duty continuous operation scenarios such as mining and large-scale earthmoving projects, due to their excellent power output, ultra-long range, and low carbon emission potential. This power system integrates multiple high-power-density components such as two methanol engines, range-extended generator sets, high-power drive motors and electronic control systems, and high-voltage power batteries. While improving the overall machine performance, it also generates unprecedented concentrated high heat loads, posing extreme challenges to the vehicle's thermal management capabilities.

[0003] Currently, the cooling systems used in traditional single-engine excavators or ordinary hybrid excavators exhibit the following significant shortcomings when applied to such complex dual-engine range-extender systems, making it difficult to meet their stringent cooling requirements:

[0004] First, there is a significant conflict between heat dissipation capacity and overall vehicle layout. The assemblies of dual engines, dual range extenders and range extender electronic controls, dual drive motors and drive electronic controls, and power batteries are large in size and generate a large amount of heat, with the total heat load far exceeding that of traditional equipment. The capacity and frontal area of ​​traditional single heat dissipation modules are limited, and simple stacking would be severely constrained by the overall vehicle layout space.

[0005] Secondly, there are issues with significant differences in heat source operating conditions and inadequate thermal management. The optimal operating temperature ranges and heat dissipation characteristics of different components in the system vary considerably: the methanol engine requires maintaining a relatively high temperature (approximately 85°C) to ensure methanol combustion efficiency, while power electronic components such as the motor and electronic control system are more temperature-sensitive and require stable operation at a lower level (approximately 65°C). Traditional single-cooling circuits cannot provide precise temperature management for each heat source, resulting in overall system inefficiency.

[0006] Secondly, energy waste is a significant issue. Traditional cooling fans often employ mechanical drives or simple electronic controls, and their speed is typically triggered by a single signal, making it impossible to precisely match the actual total heat load of the dual-engine system. For example, under light load conditions or in low-temperature environments, the fan may still continue to operate at high speed, consuming a large amount of valuable electrical energy that could be used for driving or generating electricity, directly reducing the vehicle's energy efficiency and range.

[0007] Finally, the system lacks necessary thermal safety redundancy. For critical dual-engine power sources, if their cooling systems share a core radiator, blockage, leakage, or fan failure in that radiator will lead to a significant risk of both engines overheating and shutting down simultaneously, posing a challenge to equipment reliability under harsh operating conditions.

[0008] Therefore, there is an urgent need for a heat dissipation control system that can solve the problem of coordinated heat dissipation under multiple heat sources, heavy loads, and different working conditions faced by twin-engine extended-range excavators. Summary of the Invention

[0009] In view of the problems existing in the prior art, the purpose of this invention is to provide a heat dissipation control system for a methanol dual-engine range extender excavator, so as to achieve differentiated and precise temperature control and efficient and energy-saving intelligent thermal management, and solve the problems of prominent contradiction between heat dissipation capacity and layout, extensive management of heat source differentiation, serious energy waste and insufficient system redundancy in the existing heat dissipation technology.

[0010] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0011] A heat dissipation control system for a methanol dual-engine range extender excavator, comprising:

[0012] Six independent heat dissipation modules, six water pumps corresponding to each heat dissipation module, a smart integrated valve, a thermal management control unit, and an expansion tank;

[0013] Each of the heat dissipation modules includes a radiator and at least one electric fan corresponding to the radiator; the radiator, the corresponding water pump, the intelligent integrated valve, and the excavator's power device cooling channel are connected in series to form a heat dissipation circuit;

[0014] The expansion tank is connected to six heat dissipation circuits via a main water supply pipeline and branch interfaces.

[0015] The thermal management control unit connects to and controls all electric fans, water pumps, and the intelligent integrated valve;

[0016] The excavator is equipped with an engine cooling area and a motor and electronic control cooling area. The engine cooling area has four independent cooling modules, which are respectively connected to the water cooling channel and the intake intercooling channel of the two methanol engines. The motor and electronic control cooling area has two independent cooling modules, which are respectively connected to the cooling channel of the range extender generator controller and the drive motor controller.

[0017] The intelligent integrated valve has six main channels that are connected to the heat dissipation module circuit one by one, and each main channel is equipped with a main proportional valve; a controlled bypass connection device is provided between every two main channels; the bypass connection device is configured to allow coolant to flow directionally from one main channel to another under the command of the control unit, and the flow direction is controllable.

[0018] Any two main channels are connected by two parallel bypass branches. Each bypass branch is equipped with a one-way proportional valve, and the two one-way proportional valves are in opposite directions.

[0019] The thermal management control unit is configured to perform the following control process:

[0020] Step 1: Real-time acquisition of temperature signals, cooling circuit status signals, ambient temperature, and vehicle power request signals from the engine and motor control systems;

[0021] Step 2: Dynamically adjust the control reference parameters of each heat dissipation circuit based on the vehicle power request and ambient temperature;

[0022] Step 3: Based on the collected temperature signal and the adjusted parameters, perform multi-channel feedback arbitration and power request feedforward compensation composite control on the electric fan of the motor's electronic control heat dissipation area; and perform independent linear control based on coolant temperature and intake air temperature on the electric fan of the engine heat dissipation area.

[0023] Step 4: By adjusting the opening degree of each main proportional valve in the intelligent integrated valve, the flow of each cooling circuit is allocated on demand; when it is determined that the heat dissipation capacity on the demand side is insufficient and the heat dissipation capacity on the resource side is sufficient, the coolant is controlled to be scheduled across the circuit by controlling the corresponding bypass connection device; the cross-regional scheduling process is monitored in a closed loop, and multi-level strategy upgrades are performed according to the scheduling effect.

[0024] All the electronic fans of the heat dissipation modules are evenly arranged in a dot matrix on their air intake side, and each electronic fan can be independently controlled by the thermal management control unit; the temperature signals mentioned in step 1 include: engine coolant temperature, intake intercooler temperature, motor winding temperature, controller board temperature, power device junction temperature, and coolant temperature at the inlet and outlet of each heat dissipation circuit.

[0025] The bypass connection device includes two bypass branches connected in parallel between the two main channels. Each bypass branch is equipped with a one-way proportional valve, and the two one-way proportional valves have opposite conduction directions.

[0026] Alternatively, the bypass connection device includes a bypass branch connecting the two main channels, and the bypass branch is provided with a directional adjustable bypass check valve.

[0027] The multi-channel feedback arbitration control of the electric fan in the motor's electronic control heat dissipation area in step 3 specifically includes:

[0028] The thermal management control unit defines three parallel temperature feedback channels for the heat dissipation module of each motor's electronic control heat dissipation area, and performs independent calculations based on the reference parameters set in step 2:

[0029] Channel A: Taking the winding temperature T_winding as input, when the winding temperature T_winding ≥ T_A_start, the fan is triggered to start and run at the lowest speed; when the winding temperature T_winding rises to T_A_max, the electric fan speed N_A is maintained at the highest speed; when the winding temperature is within the range of T_A_start to T_A_max, the electric fan speed N_A is adjusted according to a linear function.

[0030] Channels B and C: Taking board temperature T_board and junction temperature T_junction as inputs, the fan is triggered to start and run at the lowest speed when the board temperature T_board or junction temperature T_junction is greater than or equal to T_BC_start; when the board temperature T_board or junction temperature T_junction is greater than or equal to T_BC_max, the fan speed N_B / N_C is maintained at the highest speed; when the board temperature T_board or junction temperature T_junction is within the narrow range from T_BC_start to T_BC_max, the fan speed N_B / N_C is adjusted according to a linear function.

[0031] In each control cycle, the thermal management control unit compares the three candidate speeds N_A, N_B, and N_C calculated by channels A, B, and C for the same heat dissipation module in real time, and selects the candidate speed with the largest value as the current feedback reference speed N_feedback for the heat dissipation module.

[0032] In step 3, the composite control generates the final electronic fan control command by superimposing the feedback reference speed N_feedback with the feedforward speed generated by mapping the power request value, and then performing amplitude limiting processing. The feedforward speed N_feedforward is obtained by mapping the collected real-time power request value through a preset thermo-electric conversion model.

[0033] In step 3, for any heat dissipation module, the thermal management control unit will only drive the electronic fan of the corresponding heat dissipation module to completely stop when all the monitored temperature signals are continuously lower than the stop threshold of the corresponding channel and remain stable for a preset time. Otherwise, the electronic fan will maintain operation at the lowest speed to maintain a continuous basic heat dissipation cycle.

[0034] In step 4, the triggering conditions for the controlled cross-regional scheduling specifically include:

[0035] Insufficient demand-side capacity: The key temperature parameters of a certain target heat dissipation circuit continue to deviate from its set target, and the circuit itself has reached or approached its maximum heat dissipation capacity by adjusting the fan, indicating that its independent heat dissipation capacity has become saturated;

[0036] Resource-side capacity surplus: There is at least one other heat dissipation loop in the system, whose current thermal load status indicates that its heat dissipation capacity is significantly surplus and has the potential to provide additional heat dissipation capacity without affecting its own function.

[0037] In step 4, the multi-level strategy upgrade includes, in sequence: improving the forced heat exchange capability of the resource-side heat sink, increasing the bypass scheduling flow, initiating multi-resource collaborative scheduling, and requesting to limit the output power of heat source components;

[0038] When the temperature of the motor control area stabilizes and falls below the safety threshold, and the engine load increases and its own heat dissipation demand rises, the thermal management control unit will start the recovery program; gradually reduce the opening of the bypass valve until it is completely closed, and simultaneously restore the original opening of the main proportional valve of the engine water cooling circuit, so that the heat dissipation module returns to the independent circulation state.

[0039] The multi-level strategy upgrade operation is as follows:

[0040] Effect monitoring and preliminary judgment: After the dispatching command is executed, the thermal management control unit continuously monitors the rate of change of key temperature parameters on the demand side. If the temperature rise trend is not effectively reversed or stabilized within the preset first evaluation period, it is determined that the current borrowing plan is ineffective and intervention needs to be initiated.

[0041] The first step in the strategy upgrade is for the thermal management control unit to further explore the heat dissipation potential of the activated resource-side loops. Specific measures include: within permissible limits, further increasing the fan speed of the current resource-side heat dissipation module to enhance its own heat dissipation performance; and, provided that the system pressure and flow distribution permit, increasing the flow opening of the bypass connection device to increase the flow rate of coolant delivered from the resource side to the demand side.

[0042] In the second step of the strategy upgrade, if the demand-side temperature rise trend is not contained within the second assessment period after the execution of step one, the thermal management control unit will initiate a more complex multi-resource collaborative scheduling. At this time, other available heat dissipation loops with spare capacity will be searched and called as new resource sides. The thermal management control unit will establish parallel auxiliary flow paths from multiple resource sides to the same demand side by controlling the intelligent integrated valve.

[0043] In the third step of the strategy upgrade, if the temperature on the demand side is still out of control after the scheduling interventions in steps one and two, the thermal management control unit will determine that the cooling module's capacity has reached its limit. At this time, the thermal management control unit will immediately send a high-priority power reduction request to the vehicle controller, explicitly requesting that the output power of the corresponding heat source component be limited.

[0044] After the excavator is powered on, the thermal management control unit starts after a delay of M1 seconds and controls the electric fans of all heat dissipation modules to reverse at full speed for M2 seconds.

[0045] The thermal management control unit monitors the operating current and feedback signals of each electronic fan and water pump in real time; when a single electronic fan failure is detected, the normal electronic fans of the same heat dissipation module or adjacent heat dissipation modules are instructed to increase their speed to compensate.

[0046] By adopting the above-mentioned solution, the heat dissipation control system provided by this invention systematically solves the comprehensive heat dissipation problem faced by dual-engine extended-range excavators under multiple heat sources, high loads, and different operating conditions. This is achieved through a hardware architecture integrating independent zoned heat dissipation, evenly distributed matrix fans, and intelligent valve allocation, and by introducing intelligent control methods of multi-source arbitration and collaborative scheduling. Under the limited constraints of the vehicle's overall layout, this system achieves precise temperature management of key heat sources such as the methanol engine, drive motor, and generator controller, ensuring that each component operates within its optimal temperature range, thereby significantly improving the overall operating efficiency and reliability of the machine.

[0047] In terms of energy saving, the system dynamically predicts heat load and adjusts heat dissipation resources in advance by collecting power requests and ambient temperature in real time, effectively reducing the excessive heat dissipation phenomenon common in traditional cooling systems. The matrix-style independent control of the electronic fan and the on-demand distribution of coolant flow further reduce unnecessary energy consumption and improve the overall energy efficiency of the unit.

[0048] In terms of reliability, the system features multi-channel temperature arbitration and cross-regional redundant scheduling capabilities. When the capacity of a certain heat dissipation loop is insufficient, it can intelligently allocate the surplus heat dissipation capacity of other loops to achieve system-level thermal assistance. Even in extreme cases where some heat dissipation units fail, the system can still maintain basic operation through strategy degradation, significantly enhancing equipment availability and risk resistance under continuous heavy-load operation and harsh conditions.

[0049] Overall, this heat dissipation control system not only breaks through the limitations of traditional solutions in terms of space and capability, but also achieves a leap from passive response to active management and from local heat dissipation to system coordination through intelligent design that integrates hardware and software, providing key guarantees for the efficient, reliable and long-term operation of twin-engine extended-range excavators. Attached Figure Description

[0050] Figure 1 This is a system framework diagram of the present invention;

[0051] Figure 2 This is a flowchart of the method of the present invention. Detailed Implementation

[0052] like Figure 1As shown, this invention discloses a heat dissipation control system for a methanol dual-engine range-extended excavator, comprising six independent heat dissipation modules, six water pumps corresponding to each heat dissipation module, a smart integrated valve, a thermal management control unit (TMCU), and an expansion tank. Each heat dissipation module includes a radiator and at least one electric fan corresponding to that radiator. In this embodiment, the radiator adopts a finned + extruded flat tube core (Gill & Extruded Fin Core, abbreviated as GEF core). The electric fan is used to supply air to the radiator. The radiator, water pumps, smart integrated valve, and cooling channels of the excavator's power components constitute a heat dissipation loop. The thermal management control unit connects to and controls the electric fan, water pumps, and smart integrated valve. The expansion tank is connected to the six heat dissipation loops through a main water supply pipeline and branch interfaces, forming the system's coolant expansion compensation and exhaust hub.

[0053] Six cooling modules are located in the space at the right rear of the excavator. This space is arranged into two layers: the upper layer is for engine cooling, and the lower layer is for motor and electronic control systems. The engine cooling area has four independent cooling modules: the first, second, third, and fourth. The first module connects to the water-cooling channel of engine number one, and the second module connects to the intake intercooling channel of engine number one; the third module connects to both the water-cooling and intake intercooling channels of engine number two. The motor and electronic control system cooling area has two independent cooling modules: the fifth and sixth. The fifth module connects to the cooling channels of the two range extender generator controllers, and the sixth module connects to the cooling channels of the two drive motor controllers.

[0054] The electronic fans of the six heat dissipation modules are arranged in a dot matrix on the air intake side, and each heat dissipation module's electronic fan is independently controlled, allowing for differentiated airflow between different heat dissipation modules. In this embodiment, one radiator is equipped with three electronic fans, so twelve electronic fans are arranged on the air intake side of the engine cooling area, and six electronic fans are arranged on the air intake side of the electronically controlled cooling area. Each electronic fan is responsible for a specific heat dissipation area, forming a uniform negative pressure field, eliminating the wind speed difference between the center and edge of a traditional large fan, maximizing overall heat exchange efficiency, and reducing dead zones for heat recirculation.

[0055] The six water pumps are designated as the first water pump, the second water pump, the third water pump, the fourth water pump, the fifth water pump, and the sixth water pump, which are respectively connected to the first heat dissipation module, the second heat dissipation module, the third heat dissipation module, the fourth heat dissipation module, the fifth heat dissipation module, and the sixth heat dissipation module.

[0056] The intelligent integrated valve has six main channels, each corresponding to a heat dissipation module, and each main channel is equipped with a main proportional valve. A controlled bypass connection is provided between every two main channels, connected to the outlet side of the main proportional valve. This bypass connection is configured to allow coolant to flow directionally from one main channel to another under controllable instructions from the control unit.

[0057] In this embodiment, the bypass connection device includes a bypass branch connecting the two main channels, and a bypass one-way valve with adjustable direction is provided on the bypass branch.

[0058] The bypass connection device includes two bypass branches connected in parallel between the two main channels. Each bypass branch is equipped with a one-way proportional valve, and the two one-way proportional valves have opposite conduction directions. For example, the two main channels are a first main channel and a second main channel, and the one-way valves on the two bypass branches are a first one-way proportional valve and a second one-way proportional valve, respectively. With all water pumps and main proportional valves open, when the thermal management control unit opens the first one-way proportional valve, a portion of the coolant in the first main channel flows to the second main channel through the bypass branch; when the thermal management control unit opens the second one-way proportional valve, a portion of the coolant in the second main channel flows to the first main channel through the bypass branch.

[0059] After the excavator starts, it collects all heat-related temperature data in real time from the engine water temperature sensor, motor control temperature sensors (such as IGBT junction temperature and NTC temperature), water temperature sensors at the inlet and outlet of each cooling circuit, ambient temperature sensor, and power requests sent by the vehicle controller (VCU).

[0060] The heat dissipation control method based on the above-mentioned heat dissipation control system is executed by the thermal management control unit (TMCU), including system initialization and self-test, real-time acquisition and processing of multi-source temperature signals, dynamic target setting based on operating conditions, fan hierarchical arbitration and precise control, and intelligent distribution and redundant scheduling of coolant flow based on intelligent integrated valves. Figure 2 As shown, the specific steps are as follows:

[0061] Step 1: Real-time acquisition and filtering of multi-source temperature signals

[0062] The thermal management control unit continuously collects and filters the following key signals via CAN bus and hard-wired sensors:

[0063] Engine-related: Coolant temperature of Engine 1 and Engine 2, and temperature after intake intercooler.

[0064] Motor and electronic control related: NTC temperature and IGBT junction temperature of the range extender generator controller and drive motor controller (take the highest value among the controllers).

[0065] System status: Coolant temperature at the inlet and outlet of the six independent heat dissipation circuits.

[0066] Environment and operating conditions: ambient temperature, real-time drive power request value and range extender generator power request value from the vehicle control unit (VCU).

[0067] Before step 1, system initialization and self-test can be performed: After the vehicle is powered on (ON position), the thermal management control unit starts after a delay of M1 seconds (e.g., 3 seconds). First, it controls the electric fans of all cooling modules to reverse at full speed at maximum speed for M2 seconds (e.g., 20 seconds). This operation uses strong airflow to blow away the floating dust and debris on the surface of each radiator fin, completing an active cleaning. At the same time, it uses the current feedback of the fans to perform a preliminary check for mechanical jamming.

[0068] Step 2: Dynamic target temperature setting based on operating conditions

[0069] The thermal management control unit predicts the current operating conditions (such as light load, medium load, and heavy load) based on the collected real-time drive power, range extension power, and ambient temperature, and dynamically fine-tunes the reference parameters of each temperature control channel.

[0070] For example, in extreme high-temperature conditions where the ambient temperature is above 40°C, the starting reference temperature of the motor-controlled electronic fan is lowered from the standard value of 65°C to 62°C; in low-temperature conditions where the ambient temperature is below 0°C, it is raised to 68°C to balance heat dissipation requirements and energy saving.

[0071] At the same time, based on the received power request value, the theoretical heat dissipation load required for each heat dissipation area is calculated in advance and converted into the corresponding feedforward speed of the electric fan, N_feedforward, for early response.

[0072] Step 3: Hierarchical Arbitration and Control of Electronic Fans

[0073] After completing the acquisition of multi-source signals and dynamic parameter setting, the thermal management control unit executes a refined hierarchical arbitration control strategy and an independent linear control strategy respectively, based on the differences in heat source characteristics and protection requirements between the motor and engine heat dissipation areas, in order to achieve optimal matching of heat dissipation resources and maximize system reliability.

[0074] Step 3.1: Composite control of the electric fan in the motor's electrical control and heat dissipation area.

[0075] The motor control heat dissipation area serves power electronic components that are extremely sensitive to temperature, and its control adopts a composite intelligent algorithm of "feedforward prediction, multi-source feedback, and priority arbitration".

[0076] Step 3.1.1: Calculation of Multi-channel Feedback Reference Speed

[0077] The thermal management control unit defines three parallel temperature feedback channels for each motor control heat dissipation module (i.e., the fifth and sixth heat dissipation modules), and performs independent calculations based on the reference parameters dynamically set in step 3:

[0078] Channel A (based on motor winding temperature): Taking the winding temperature T_winding as input, when the winding temperature T_winding ≥ T_A_start (e.g., 65℃), the fan is triggered to start and run at the lowest speed (e.g., 25% of the maximum speed). When the winding temperature T_winding rises to T_A_max (e.g., 95℃), the electric fan speed N_A remains at the maximum speed (100% of the maximum speed). When the winding temperature is within the range of T_A_start to T_A_max, the electric fan speed N_A is adjusted according to a linear function (e.g., divided into 10 linear speed control levels).

[0079] Channel B (based on controller board temperature NTC) and Channel C (based on IGBT estimated junction temperature): The board temperature T_board and junction temperature T_junction are used as inputs. When the board temperature T_board or junction temperature T_junction ≥ T_BC_start (e.g., 45℃), the fan is triggered to start and operate at the lowest speed (e.g., 25% of maximum speed). When the board temperature T_board or junction temperature T_junction ≥ T_BC_max (e.g., 50℃), the electric fan speed N_B / N_C is maintained at the maximum speed (100% of maximum speed). When the board temperature T_board or junction temperature T_junction is within the narrow range of T_BC_start to T_BC_max, the electric fan speed N_B / N_C is adjusted linearly (e.g., divided into 5 linear speed control levels).

[0080] Step 3.1.2: Priority Arbitration and Feedback Benchmark Determination

[0081] In each control cycle, the thermal management control unit compares in real time the three candidate speeds N_A, N_B, and N_C calculated by channels A, B, and C for the same heat dissipation module. Based on the arbitration principle of "first come, first served; largest value selected," the candidate speed with the largest value is chosen as the current feedback reference speed N_feedback for that region. This mechanism ensures an instantaneous response to any abnormal rise in temperature at any critical point.

[0082] Step 3.1.3: Feedforward-Feedback Command Synthesis and Output

[0083] To achieve proactive control, the thermal management control unit superimposes the aforementioned feedback reference speed N_feedback and feedforward compensation speed N_feedforward. N_feedforward is derived from the real-time power request value acquired in step (2) through a preset heat-to-electric conversion model, directly reflecting the upcoming heat load. The synthesized target speed N_target = N_feedback + N_feedforward. Subsequently, the thermal management control unit performs upper and lower limit processing on the target speed N_target (e.g., limiting it between N_min and N_max), and finally converts it into a duty cycle adjustable PWM signal to drive the dot matrix electronic fan group corresponding to the heat dissipation module, achieving smooth, precise and rapid airflow adjustment.

[0084] Step 3.2: Independent linear control of the electric fan in the engine cooling area

[0085] The engine cooling area is mainly designed for the water-cooling system and the turbocharged intercooling system of the methanol engine. Since the two systems have different thermal inertia and operating temperature ranges, they adopt independent and parallel control strategies without cross arbitration.

[0086] Step 3.2.1, Engine water-cooled electric fan control (electric fans of the first and third heat dissipation modules).

[0087] For each engine's coolant temperature T_coolant, the thermal management control unit performs single-input single-output control. When the coolant temperature T_coolant ≥ T_D_start (e.g., 65°C), the corresponding electric fan starts rotating and operates at its lowest speed. When the coolant temperature T_coolant ≥ T_D_max (e.g., 98°C), the electric fan continuously operates at its highest speed. When the coolant temperature T_coolant is within the range of T_D_start to T_D_max, the electric fan speed increases linearly with temperature.

[0088] Step 3.2.2: Engine intercooler electric fan control (electric fans of the second and fourth heat dissipation modules)

[0089] For each engine, the thermal management control unit independently controls the intercooler electric fan based on the intercooler temperature T_air_intake. When the intercooler temperature T_air_intake is greater than or equal to T_E_start (e.g., 50°C), the electric fan starts and operates at its lowest speed. When the intercooler temperature T_air_intake reaches T_E_max, the electric fan operates at full speed. When the intercooler temperature T_air_intake is within the range of T_E_start to T_E_max (e.g., 70°C), the electric fan speed is linearly adjusted to ensure intake air density and prevent knocking.

[0090] Step 3.3, Control Exit (Stop) Conditions

[0091] To reduce the frequency of component operation and ensure basic heat exchange, a stringent shutdown logic is implemented. For any heat dissipation module, the thermal management control unit will only drive the corresponding heat dissipation module's electric fan to completely stop if all monitored temperature signals remain consistently below the corresponding channel's stop threshold [this stop threshold is the start threshold minus a hysteresis amount (e.g., 3-5°C)] and remain stable for a preset period of time (e.g., 30 seconds). Otherwise, the electric fan will maintain operation at the lowest speed (e.g., 10% of rated speed) to maintain continuous basic heat dissipation circulation.

[0092] Step 4: Intelligent allocation and redundancy scheduling of coolant flow

[0093] The thermal management control unit achieves overall optimized management of the liquid flow and path of the entire cooling system and cross-regional redundancy and mutual assistance through coordinated control of intelligent integrated valves. Its core is the intelligent valve control strategy of "on-demand allocation, dynamic scheduling, and closed-loop recovery".

[0094] Step 4.1: On-demand traffic allocation under normal circumstances

[0095] The thermal management control unit dynamically calculates the real-time coolant demand based on the inlet temperature difference, flow rate, and estimated heat load of each circuit collected in step (2). By sending precise PWM commands to the corresponding electronically controlled proportional valve in the intelligent integrated valve, its opening is continuously adjusted to control the coolant flow to each independent heat dissipation module. For example, when the drive motor is continuously outputting high power, the thermal management control unit will increase the opening of the proportional valve flowing to the main channel of the sixth heat dissipation module (drive electronically controlled heat dissipation) to ensure sufficient coolant to remove heat; conversely, in standby mode, the opening is reduced to reduce the parasitic power consumption of the water pump.

[0096] Step 4.2: Triggering Conditions and Redundancy Scheduling Decisions

[0097] When the system detects the following combined conditions, the thermal management control unit determines that cross-zone redundant coolant scheduling needs to be initiated (taking the scheduling from the engine water-cooled zone to the overheated motor electronic control zone as an example):

[0098] Insufficient demand-side capacity: The key temperature parameters of a target heat dissipation circuit continuously deviate from its set target, and the circuit itself has reached or approached its maximum heat dissipation capacity through adjustments to fans, water pumps, etc., indicating that its independent heat dissipation capacity is approaching saturation. For example, if a key temperature point in the motor control area (such as the IGBT junction temperature) exceeds the first-level alarm threshold (such as 60°C), and the speed of the matrix fan in the motor control heat dissipation area has been increased to above the preset high-efficiency speed limit, but the temperature rise trend has not been effectively curbed, it indicates that its own heat dissipation circuit has reached or is close to saturation.

[0099] Resource-side capacity surplus: At least one other heat dissipation loop exists in the system, and its current thermal load status indicates that its heat dissipation capacity is significantly surplus, possessing the potential to provide additional heat dissipation capacity without affecting its own function. For example, if Engine No. 1 is under medium to low load, the outlet water temperature of its water-cooled loop is significantly lower than its optimal operating temperature limit (e.g., 80°C), possessing the potential to provide additional cooling capacity.

[0100] Step 4.3, Execution process for cross-regional secondment

[0101] Once the scheduling conditions are met, the thermal management control unit immediately performs the following sequential operations via the intelligent integrated valve:

[0102] Establish a controlled auxiliary flow path: While maintaining the independence of each main circuit, the thermal management control unit controls the opening of the bypass check valve to direct the coolant from the resource side to the demand side, forming a controlled auxiliary connection with a limited flow rate.

[0103] Achieve directional transfer of cooling capacity: A portion of the coolant at a suitable temperature from the resource-side loop is directed into the inlet of the demand-side loop, where it mixes with the existing coolant, thereby rapidly improving the instantaneous heat dissipation capacity of the demand side.

[0104] Dynamic balance control: The thermal management control unit dynamically fine-tunes the bypass flow and corresponding electric fans based on real-time feedback of the critical temperature on the demand side, so as to achieve dynamic matching between the supplied cooling capacity and the changing heat load.

[0105] In the application example, firstly, the main proportional valve of the main channel of the engine water cooling circuit (resource side) is slightly adjusted to increase its opening slightly; at the same time, the bypass check valve is opened to allow the coolant in the engine water cooling circuit to flow to the target motor control circuit.

[0106] Through the above operations, a portion of the coolant from the No. 1 engine radiator, which has a lower temperature (approximately 15%-30% of the total flow in this circuit), is controllably diverted and injected directly into the main channel corresponding to the motor control circuit via a bypass branch. It then flows into the inlet pipe of the overheated motor control radiator, rapidly mixing with its own higher-temperature coolant, thereby directly and quickly reducing its inlet temperature. The thermal management control unit dynamically fine-tunes the opening of the bypass check valve and the speed of the electric fan in the No. 1 engine cooling module based on the real-time rate of change of key temperature points in the motor control area, achieving an instantaneous balance between cooling capacity supply and demand.

[0107] Step 4.4: Closed-loop verification of scheduling effect and strategy upgrade

[0108] The thermal management control unit performs closed-loop monitoring and evaluation of the scheduling process to ensure effectiveness and prevent side effects.

[0109] Effectiveness monitoring and preliminary assessment: After the dispatch command is executed, the thermal management control unit continuously monitors the rate of change of key temperature parameters on the demand side (such as IGBT junction temperature). If the temperature rise trend is not effectively reversed or stabilized within the preset first evaluation period (such as 30 seconds), the current borrowing plan is deemed insufficient, and intervention is required.

[0110] Strategy upgrade step one: Deeply explore the potential of current resources;

[0111] First, the thermal management control unit attempts to further explore the heat dissipation potential of the already enabled resource-side loops. Specific measures include:

[0112] Enhance forced heat exchange capability: Within permissible limits, further increase the fan speed of the current resource-side heat dissipation module to enhance its own heat dissipation efficiency, thereby providing coolant at a lower temperature.

[0113] Increase the flow rate: Under the premise of system pressure and flow distribution allowance, appropriately increase the opening of the bypass check valve on the bypass branch to increase the flow rate of coolant delivered from the resource side to the demand side.

[0114] This step aims to improve scheduling efficiency by enhancing the heat exchange and flow capacity of the current path without changing the scheduling topology.

[0115] Strategy upgrade step two: Initiate multi-resource collaborative scheduling

[0116] If, after step one, the demand-side temperature rise trend remains unchecked during the second assessment period, the thermal management control unit will initiate a more complex multi-resource coordinated scheduling. At this point, the system will search for and utilize other available and redundant cooling circuits (e.g., the intercooler circuit of another engine or another motor control circuit) as new resource sides. The thermal management control unit, by controlling intelligent integrated valves, establishes parallel auxiliary flow paths from multiple resource sides to the same demand side, achieving a "many-to-one" coordinated supply of cooling capacity to cope with extreme heat load shocks.

[0117] Strategy upgrade step three: Implement demand management on the heat source side.

[0118] If, after the aforementioned multi-level scheduling interventions, the temperature on the demand side remains out of control and approaches the safety threshold, the thermal management control unit will determine that the cooling system's capacity has reached its limit and intervention at the source of the heat must be initiated. At this point, the thermal management control unit immediately sends a high-priority power reduction request to the vehicle control unit (VCU) via the CAN bus, explicitly requesting that the output power of the corresponding heat source component (such as the drive motor or range extender generator) be limited. This measure directly reduces heat generation at its source and is the ultimate and necessary control method to ensure the safety of the system hardware.

[0119] Step 4.5: Automatic System Recovery and Thermal Isolation

[0120] Automatic Recovery: When the temperature in the motor's electronic control area stabilizes below the safe threshold, and the engine load increases and its own heat dissipation demand rises, the thermal management control unit will initiate a recovery procedure. It will smoothly and gradually reduce the opening of the bypass valve until it is completely closed, and simultaneously restore the original opening of the main proportional valve of the engine's water-cooling circuit, so that the two (or more) cooling modules automatically and seamlessly return to an independent circulation state, preventing the engine from overheating due to "assisting" others.

[0121] The principle of minimizing thermal interference: Throughout the entire cross-regional borrowing process, by precisely controlling the bypass flow (with only a small amount of mixing) and using bypass check valves for isolation, it is ensured that the large loops with different temperatures and different working medium requirements (such as engine high-temperature coolant and electronically controlled low-temperature coolant) are not physically completely merged. This minimizes the risk of mutual thermal interference between different heat sources and maintains the optimal performance of each system when it operates independently.

[0122] Step 5: Fault Diagnosis and Degradation Strategy

[0123] The thermal management control unit monitors the operating current and feedback signals of each electric fan and water pump in real time. When a single electric fan failure is detected, it can instruct the normal electric fans of the same heat dissipation module or adjacent heat dissipation modules to increase their speed to compensate.

[0124] If the water temperature in a certain cooling circuit spikes abnormally and all adjustment measures are ineffective, the thermal management control unit will send a power reduction request to the VCU via the CAN bus to limit the output of the corresponding power components in order to ensure system safety.

[0125] Compared with the prior art, the present invention has the following significant advantages:

[0126] Highly efficient and compact, solving layout challenges: Through a hardware architecture of "independent zoned heat dissipation, evenly distributed matrix fans, and intelligent valve allocation," precise "point-to-point" cooling of each heat source is achieved within the limited engine compartment space of the dual-engine extended-range excavator. This ensures that the drive motor control system, range extender motor control system, and engine all operate within their respective optimal temperature ranges, improving the overall reliability and efficiency of the machine.

[0127] Significant energy-saving effect: The integrated valve block series and parallel water circuit design realizes intelligent thermal energy distribution between cold and heat sources, and the local precise control of the electronic dot matrix fan avoids unnecessary energy consumption.

[0128] High control precision and response speed: The multi-source arbitration mechanism of "first come, first served" ensures instantaneous response to the hottest spot, effectively protects low-temperature and fragile components, and extends the system life.

[0129] High reliability and redundancy: The multi-zone physical isolation design combined with the software's heat dissipation strategy reconstructs the system's built-in idle heat dissipation capacity, achieving high-performance system-level redundancy and ensuring the reliable operation of the entire machine. Local failures of a single heat dissipation module no longer cause the entire machine to fail and shut down.

[0130] The above description is merely an embodiment of the present invention and does not constitute any limitation on the technical scope of the present invention. Therefore, any minor modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention shall still fall within the scope of the technical solution of the present invention.

Claims

1. A heat dissipation control system for a methanol dual-engine range extender excavator, characterized in that, include: Six independent heat dissipation modules, six water pumps corresponding to each heat dissipation module, a smart integrated valve, a thermal management control unit, and an expansion tank; Each of the heat dissipation modules includes a radiator and at least one electric fan corresponding to the radiator; the radiator, the corresponding water pump, the intelligent integrated valve, and the excavator's power device cooling channel are connected in series to form a heat dissipation circuit; The expansion tank is connected to six heat dissipation circuits via a main water supply pipeline and branch interfaces. The thermal management control unit connects to and controls all electric fans, water pumps, and the intelligent integrated valve; The excavator is equipped with an engine cooling area and a motor and electronic control cooling area. The engine cooling area has four independent cooling modules, which are respectively connected to the water cooling channel and the intake intercooling channel of the two methanol engines. The motor and electronic control cooling area has two independent cooling modules, which are respectively connected to the cooling channel of the range extender generator controller and the drive motor controller. The intelligent integrated valve has six main channels that are connected to the heat dissipation module circuit one by one, and each main channel is equipped with a main proportional valve; a controlled bypass connection device is provided between every two main channels; the bypass connection device is configured to allow coolant to flow directionally from one main channel to another under the command of the thermal management control unit, and the flow direction is controllable. The thermal management control unit is configured to perform the following control process: Step 1: Real-time acquisition of temperature signals, cooling circuit status signals, ambient temperature, and vehicle power request signals from the engine and motor control systems; Step 2: Dynamically adjust the control reference parameters of each heat dissipation circuit based on the vehicle power request and ambient temperature; Step 3: Based on the collected temperature signal and the adjusted parameters, perform multi-channel feedback arbitration and power request feedforward compensation composite control on the electric fan of the motor's electronic control heat dissipation area; and perform independent linear control based on coolant temperature and intake air temperature on the electric fan of the engine heat dissipation area. Step 4: By adjusting the opening degree of each main proportional valve in the intelligent integrated valve, the flow of each cooling circuit is allocated on demand; when it is determined that the heat dissipation capacity on the demand side is insufficient and the heat dissipation capacity on the resource side is sufficient, the coolant is controlled to be scheduled across the circuit by controlling the corresponding bypass connection device; the cross-regional scheduling process is monitored in a closed loop, and multi-level strategy upgrades are performed according to the scheduling effect.

2. The heat dissipation control system for a methanol dual-engine range extender excavator according to claim 1, characterized in that, All the electronic fans of the heat dissipation modules are evenly arranged in a dot matrix on their air intake side, and each electronic fan can be independently controlled by the thermal management control unit; the temperature signals mentioned in step 1 include: engine coolant temperature, intake intercooler temperature, motor winding temperature, controller board temperature, power device junction temperature, and coolant temperature at the inlet and outlet of each heat dissipation circuit.

3. The heat dissipation control system for a methanol dual-engine range extender excavator according to claim 1, characterized in that, The bypass connection device includes two bypass branches connected in parallel between the two main channels. Each bypass branch is equipped with a one-way proportional valve, and the two one-way proportional valves have opposite conduction directions. Alternatively, the bypass connection device includes a bypass branch connecting the two main channels, and the bypass branch is provided with a directional adjustable bypass check valve.

4. The heat dissipation control system for a methanol dual-engine range extender excavator according to claim 1, characterized in that, The multi-channel feedback arbitration control of the electric fan in the motor's electronic control heat dissipation area in step 3 specifically includes: The thermal management control unit defines three parallel temperature feedback channels for the heat dissipation module of each motor's electronic control heat dissipation area, and performs independent calculations based on the reference parameters set in step 2: Channel A: Taking the winding temperature T_winding as input, when the winding temperature T_winding ≥ T_A_start, the electric fan is triggered to start and runs at the lowest speed; when the winding temperature T_winding rises to T_A_max, the electric fan speed N_A is maintained at the highest speed; when the winding temperature is within the range of T_A_start to T_A_max, the electric fan speed N_A is adjusted according to a linear function. Channels B and C: Taking board temperature T_board and junction temperature T_junction as inputs, the electric fan is triggered to start when board temperature T_board or junction temperature T_junction ≥ T_BC_start, and runs at the lowest speed; when board temperature T_board or junction temperature T_junction ≥ T_BC_max, the electric fan speed N_B / N_C is maintained at the highest speed; when board temperature T_board or junction temperature T_junction is within the narrow range of T_BC_start to T_BC_max, the electric fan speed N_B / N_C is adjusted according to a linear function. In each control cycle, the thermal management control unit compares the three candidate speeds N_A, N_B, and N_C calculated by channels A, B, and C for the same heat dissipation module in real time, and selects the candidate speed with the largest value as the current feedback reference speed N_feedback for the heat dissipation module.

5. The heat dissipation control system for a methanol dual-engine range extender excavator according to claim 4, characterized in that, In step 3, the composite control generates the final electronic fan control command by superimposing the feedback reference speed N_feedback with the feedforward speed generated by mapping the power request value, and then performing amplitude limiting processing. The feedforward speed N_feedforward is obtained by mapping the collected real-time power request value through a preset thermo-electric conversion model.

6. The heat dissipation control system for a methanol dual-engine range extender excavator according to claim 1, characterized in that, In step 3, for any heat dissipation module, the thermal management control unit will only drive the electronic fan of the corresponding heat dissipation module to completely stop when all the monitored temperature signals are continuously lower than the stop threshold of the corresponding channel and remain stable for a preset time. Otherwise, the electronic fan will maintain operation at the lowest speed to maintain a continuous basic heat dissipation cycle.

7. The heat dissipation control system for a methanol dual-engine range extender excavator according to claim 1, characterized in that, In step 4, the triggering conditions for the controlled cross-regional scheduling specifically include: Insufficient demand-side capacity: The key temperature parameters of a certain target heat dissipation circuit continue to deviate from its set target, and the circuit itself has reached or approached its maximum heat dissipation capacity by adjusting the electric fan, indicating that its independent heat dissipation capacity has become saturated. Resource-side capacity surplus: There is at least one other heat dissipation loop in the system, whose current thermal load status indicates that its heat dissipation capacity is significantly surplus and has the potential to provide additional heat dissipation capacity without affecting its own function.

8. The heat dissipation control system for a methanol dual-engine range extender excavator according to claim 7, characterized in that, In step 4, the multi-level strategy upgrade includes, in sequence: improving the forced heat exchange capability of the resource-side heat sink, increasing the bypass scheduling flow, initiating multi-resource collaborative scheduling, and requesting to limit the output power of heat source components; When the temperature of the motor control area stabilizes and falls below the safety threshold, and the engine load increases and its own heat dissipation demand rises, the thermal management control unit will start the recovery program; gradually reduce the opening of the bypass valve until it is completely closed, and simultaneously restore the original opening of the main proportional valve of the engine water cooling circuit, so that the heat dissipation module returns to the independent circulation state.

9. The heat dissipation control system for a methanol dual-engine range extender excavator according to claim 8, characterized in that, The multi-level strategy upgrade operation is as follows: Effect monitoring and preliminary judgment: After the dispatching command is executed, the thermal management control unit continuously monitors the rate of change of key temperature parameters on the demand side. If the temperature rise trend is not effectively reversed or stabilized within the preset first evaluation period, it is determined that the current borrowing plan is ineffective and intervention needs to be initiated. The first step in the strategy upgrade is for the thermal management control unit to further explore the heat dissipation potential of the activated resource-side loops. Specific measures include: within permissible limits, further increasing the fan speed of the current resource-side heat dissipation module to enhance its own heat dissipation performance; and, provided that the system pressure and flow distribution permit, increasing the flow opening of the bypass connection device to increase the flow rate of coolant delivered from the resource side to the demand side. In the second step of the strategy upgrade, if the demand-side temperature rise trend is not contained within the second assessment period after the execution of step one, the thermal management control unit will initiate a more complex multi-resource collaborative scheduling. At this time, other available heat dissipation loops with spare capacity will be searched and called as new resource sides. The thermal management control unit will establish parallel auxiliary flow paths from multiple resource sides to the same demand side by controlling the intelligent integrated valve. In the third step of the strategy upgrade, if the temperature on the demand side is still out of control after the scheduling intervention in steps one and two, the thermal management control unit will determine that the cooling module's capacity has reached its limit. At this time, the thermal management control unit will immediately send a high-priority power reduction request to the vehicle controller, explicitly requesting that the output power of the corresponding heat source component be limited.

10. The heat dissipation control system for a methanol dual-engine range extender excavator according to claim 1, characterized in that, After the excavator is powered on, the thermal management control unit starts after a delay of M1 seconds and controls the electric fans of all heat dissipation modules to reverse at full speed for M2 seconds. The thermal management control unit monitors the operating current and feedback signals of each electronic fan and water pump in real time; when a single electronic fan failure is detected, the normal electronic fans of the same heat dissipation module or adjacent heat dissipation modules are instructed to increase their speed to compensate.

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