Temperature control system for intercooler of engine test bed

Abstract

The invention discloses an engine test bed intercooler temperature control system comprising an intercooler used for simulating work under actual working conditions; the constant-temperature heater is used for heating the cooling liquid to a preset temperature; the electronic water pump is used for driving cooling liquid to circulate and controllable in flow; the plate heat exchanger is used for heat exchange between the external circulation chilled water and the internal circulation cooling liquid; the expansion kettle is connected into the circulating system through a three-way valve to realize water replenishing and pressure balance; the bypass valve is arranged on the water pump bypass pipeline and used for adjusting the internal circulation flow and pressure, and the PID proportional valve is arranged on the external circulation chilled water pipeline and used for dynamically adjusting the external circulation chilled water flow; and the flow meter and the temperature and pressure sensor are used for monitoring the flow and pressure of the cooling liquid and the temperature of the outlet gas of the intercooler in real time.

Description

Technical Field

[0001] The present invention relates to the field of internal combustion engine testing technology, and more specifically to an intercooler temperature control system and control logic for an engine test bench, and more particularly to a method for dynamically adjusting the intercooler gas temperature, which achieves a highly simulated and high-precision temperature control effect through multivariable coordinated control of internal and external loops. Background Art

[0002] Traditional engine intercooler test benches mostly use a single cooling or heating mode, which makes it difficult to simulate the dynamic temperature changes under real working conditions.

[0003] The main issues include: insufficient cleanliness in the circulation system, allowing impurities in the gas to easily enter the internal combustion engine, resulting in damage to the internal combustion engine sample or deviations in test data. Low temperature control accuracy and slow response speeds fail to meet the requirements of high-simulation testing. The system layout is complex, maintenance costs are high, and there are discrepancies between the control logic and the actual vehicle.

[0004] To address these challenges, a temperature control system with both heating and cooling capabilities and dynamic adjustment must be developed. The cleanliness and temperature control stability of the circulation system must be improved, safety must be enhanced, and experimental errors must be reduced. The system structure must be simplified, manufacturing costs must be reduced, and the system must be tailored to the actual vehicle operating conditions. Summary of the Invention

[0005] In view of the deficiencies in the prior art, the present invention provides an engine test bench intercooler temperature control system to solve the above problems and improve the accuracy and efficiency of engine testing.

[0006] To achieve the above object, the present invention provides the following technical solutions: An engine test bench intercooler temperature control system includes an intercooler for simulating operation under actual working conditions; a constant temperature heater for heating the coolant to a preset temperature; an electronic water pump for driving the coolant circulation with controllable flow; a plate heat exchanger for heat exchange between external circulating chilled water and internal circulating coolant; an expansion kettle connected to the circulation system through a three-way valve to achieve water replenishment and pressure balance; a bypass valve and a PID proportional valve, wherein the bypass valve is arranged in the water pump bypass pipeline for adjusting the internal circulation flow and pressure, and the PID proportional valve is arranged in the external circulating chilled water pipeline for dynamically adjusting the external circulating chilled water flow; a flow meter and a temperature and pressure sensor for real-time monitoring of the coolant flow, pressure and intercooler outlet gas temperature; a controller, based on the real-time monitored temperature signal, realizes internal circulation water temperature control by controlling the constant temperature heater target temperature and the PID proportional valve and multivariable collaborative control, and realizes gas temperature control by combining the bypass valve to adjust the water flow distribution.

[0007] As a further solution of the present invention, the electronic water pump is a PWM variable frequency pump.

[0008] As a further solution of the present invention, a filter element and a filter screen are also included, which are respectively arranged at the water inlet of the plate heat exchanger and the external circulation pipeline to ensure the cleanliness of the circulating medium.

[0009] As a further embodiment of the present invention, the external circulation pipeline sequentially connects a chilled water source, a filter element, a PID proportional valve, the external circulation side of the plate heat exchanger, and discharges or returns to the chilled water system. In the external circulation loop, the chilled water source (7°C) is connected to the filter element, which is connected to the PID proportional valve, which is connected to the external circulation side of the plate heat exchanger. Chilled water on the external circulation side of the plate heat exchanger can be discharged or returned to the chilled water system.

[0010] As a further embodiment of the present invention, the water outlet of an electronic water pump, a flow meter, an intercooler water inlet, an intercooler water outlet, a thermostatic heater, an internal circulation side water inlet of a plate heat exchanger, a filter, an internal circulation side water outlet of a plate heat exchanger, and an electronic water pump water inlet are connected in sequence to form an internal circulation loop. In the internal circulation loop, the water outlet of the electronic water pump is connected to the flow meter, which is connected to the water inlet of the engine intercooler, which is connected to the thermostatic heater, which is connected to the internal circulation side water inlet of the plate heat exchanger, which is connected to the filter, which is connected to the internal circulation side water outlet of the plate heat exchanger, which is connected to the electronic water pump water inlet. A proportional valve is provided in the water pump bypass line to adjust the internal circulation flow and pressure.

[0011] As a further solution of the present invention, the expansion kettle is connected between the water outlet of the intercooler and the thermostatic heater through a three-way valve. The expansion kettle is connected between the water outlet of the intercooler and the thermostatic heater through a three-way valve to maintain a stable system pressure.

[0012] As a further solution of the present invention, the temperature control process is as follows: temperature target setting, setting the target temperature of the intercooler outlet gas according to the test requirements; dynamic adjustment strategy: in the heating stage, the external circulation PID proportional valve is closed, the constant temperature heater is working, and the electronic water pump adjusts the speed according to the preset flow curve; in the cooling stage, the external circulation PID proportional valve adjusts the opening according to the control algorithm, and the electronic water pump and the bypass valve cooperate to adjust the internal circulation flow; in the constant temperature stage: balancing the heating and cooling power through a multivariable collaborative control algorithm; PID algorithm optimization: adaptive PID parameter adjustment, the controller monitors the dynamic characteristics of the system in real time and automatically adjusts the proportional, integral, and differential parameters; fuzzy-PID composite control: introducing a fuzzy control rule library, dynamically correcting the PID parameters according to the temperature deviation and the deviation change rate; multivariable collaborative control: multi-parameter decoupling control: establishing a mathematical model with temperature, internal circulation pressure, and coolant flow as state variables, and designing a decoupling controller; predictive control algorithm: constructing an ARIMA prediction model based on historical data, predicting the temperature change trend in advance, and generating feedforward control instructions; cleanliness assurance: preventing impurities from entering the intercooler and plate exchanger through double filtration of the internal circulation filter and the external circulation filter element.

[0013] As a further solution of the present invention, by monitoring the signal of the water flowmeter, the bypass valve is controlled to achieve the control of the water system flow distribution. Meanwhile, the working frequency of the electronic water pump is controlled to finely adjust the water pressure and the total water system flow; a pressure measurement point is added at the water flowmeter, and the working state of the electronic water pump is judged according to the flow and pressure. When there is no flow / pressure, the operating system is linked to alarm.

[0014] As a further solution of the present invention, the introduction of the fuzzy control rule base specifically includes mapping the temperature deviation (e) and the deviation change rate (Δe) into fuzzy quantities, dynamically correcting the PID parameters. When |e|>2°C, the fuzzy controller dominates the regulation to quickly reduce the deviation; when |e|<1°C, it switches to the PID precise control mode.

[0015] As a further solution of the present invention, the multi-parameter decoupling control specifically includes establishing a mathematical model with temperature (T), internal circulation pressure (P), and coolant flow (Q) as state variables and designing a decoupling controller: , where u1 and u2 respectively correspond to the rotational speed of the electronic water pump and the opening command of the PID proportional valve, to achieve the dynamic balance of temperature-pressure-flow, and T arget is the target temperature of the gas at the outlet of the intercooler.

[0016] The specific control logic in the present invention is as follows: Temperature target setting: Set the target temperature of the gas at the outlet of the intercooler (Ttarget) according to the test requirements. Dynamic adjustment strategy: Heating stage (T_measured < T_target): The external circulation proportional valve is closed, and the constant temperature heater works to heat the coolant to the set temperature (such as 45°C). The electronic water pump adjusts the rotational speed according to the preset flow curve to ensure that the high-temperature coolant fully flows through the intercooler to achieve rapid heating of the gas. Cooling stage (T_measured > T_target): The external circulation PID proportional valve adjusts the opening according to the control algorithm, and reduces the temperature of the internal circulation coolant through the plate heat exchanger; the electronic water pump and the bypass valve cooperate to adjust the internal circulation flow to ensure the maximum heat exchange efficiency of the low-temperature coolant in the intercooler. Constant temperature stage (T_measured ≈ T_target): Balance the heating and cooling powers through the multi-variable cooperative control algorithm to maintain the temperature fluctuation range ≤ ±0.5°C.

[0017] PID Algorithm Optimization: Adaptive PID Parameter Adjustment: The controller monitors system dynamic characteristics in real time, including temperature change rate and deviation, and automatically adjusts proportional (Kp), integral (Ki), and differential (Kd) parameters. During engine startup or when temperature changes rapidly, Kp is increased to improve response speed, while Ki is reduced to prevent integral windup. When the temperature approaches the setpoint, Kp is reduced and Ki is increased to suppress overshoot and eliminate steady-state error. Experimental data shows that the adaptive PID algorithm can improve temperature control accuracy to ±0.5°C. Fuzzy-PID Composite Control: Introducing a fuzzy control rule base, the temperature deviation (e) and the rate of change of the deviation (Δe) are mapped into fuzzy variables, dynamically adjusting the PID parameters. When |e|>2°C, the fuzzy controller takes control, rapidly reducing the deviation. When |e|<1°C, it switches to PID precision control mode. Comparative testing shows that this algorithm reduces system response time by 25%-30% and improves interference rejection by 40%. Multivariable Collaborative Control: Multi-Parameter Decoupling Control: A mathematical model with temperature (T), internal circulation pressure (P), and coolant flow (Q) as state variables is established, and a decoupling controller is designed. u1 and u2 correspond to the electronic water pump speed and PID proportional valve opening command, respectively, to achieve a dynamic balance between temperature, pressure, and flow. A predictive control algorithm: An ARIMA forecasting model is constructed based on historical data to predict temperature trends 5-10 seconds in advance and generate feedforward control commands. When the temperature is predicted to exceed the setpoint, the external circulation chilled water flow is increased in advance. When engine operating conditions suddenly change (such as a sudden load increase), the heater power and bypass valve opening are synchronously adjusted to suppress temperature fluctuations. Simulation results show that predictive control can reduce steady-state fluctuations by 60%. Cleanliness Assurance: Dual filtration by the internal circulation filter and external circulation filter effectively prevents impurities from entering the intercooler and plate heat exchanger, ensuring clean and reliable system operation.

[0018] The present invention has the following beneficial effects: High degree of simulation: The intercooler of the entire vehicle is directly adopted, and the pressure and flow control are close to the actual working conditions, which can truly simulate the working state of the intercooler in the actual operation of the engine.

[0019] Precise temperature control: PID algorithm combined with dual-loop coordinated control achieves high-precision temperature regulation with a temperature regulation accuracy of up to ±0.5°C.

[0020] Fast response and intelligence: Multivariable collaborative control shortens the system response time to less than 3 seconds, significantly enhancing the ability to adapt to dynamic working conditions; the adaptive algorithm reduces the workload of manual parameter setting and improves the system's intelligence level.

[0021] Clean and reliable: The multi-stage filtration design effectively avoids pipe blockage, extends the life of the equipment, and ensures stable and reliable operation of the system.

[0022] Cost and maintenance advantages: The modular layout allows for quick replacement of components, reducing maintenance difficulty and cost; the bypass proportional valve reduces the water pump load energy consumption, saving energy.

[0023] In order to more clearly illustrate the structural features and effects of the present invention, the present invention is described in detail below with reference to the accompanying drawings and specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 The present invention is a schematic structural diagram of an engine test bench intercooler temperature control system. DETAILED DESCRIPTION

[0025] The present invention will be further described below with reference to the accompanying drawings and related knowledge, and described clearly and completely. Obviously, the described applications are only part of the embodiments of the present invention, rather than all of the embodiments.

[0026] See also Figure 1 As shown, an engine test bench intercooler temperature control system includes an intercooler for simulating operation under actual working conditions. It is further preferred to directly use the original vehicle intercooler to ensure test simulation and cleanliness. The intercooler uses the original vehicle intercooler to highly restore the actual working conditions, which not only ensures the test simulation, but also ensures the cleanliness of the circulating medium and prevents impurities from interfering with the test results. The constant temperature heater is used to heat the coolant to a preset temperature. It is responsible for heating the coolant to a preset temperature range, which is usually 25-70°C. This preset temperature can be flexibly adjusted according to different test requirements, providing the system with the ability to adapt to various working conditions.

[0027] The electronic water pump is used to circulate the coolant with controllable flow. Specifically, it drives the coolant through the system and provides precise flow control. To achieve more accurate and flexible flow regulation, the system uses a PWM variable frequency pump as the electronic water pump. This pump can adjust its operating frequency in real time according to actual needs, thereby precisely controlling the coolant flow and ensuring stable system operation. Plate heat exchangers (PHEs) are key components for heat exchange, exchanging heat between externally circulating chilled water (7°C) and internally circulating coolant. Through efficient heat exchange between the externally circulating 7°C chilled water and the internally circulating coolant, the temperature of the internally circulating coolant is regulated. This heat exchange method quickly and effectively changes the coolant temperature, meeting the system's requirements for timely temperature control.

[0028] The expansion kettle, connected to the circulation system via a three-way valve, provides water replenishment and pressure balance. During system operation, the expansion kettle automatically adjusts the water volume based on changes in system pressure, ensuring stable pressure and preventing damage from pressure fluctuations.

[0029] Bypass valve and PID proportional valve: The bypass valve is installed in the water pump bypass line, while the PID proportional valve is installed in the external circulation chilled water line. Together, they fulfill the important task of dynamically regulating liquid flow and pressure. The PID proportional valve can precisely adjust the flow of the external circulation chilled water based on real-time data feedback from the system, achieving precise control of the heat exchange process.

[0030] Flow meter and temperature and pressure sensor: Real-time monitoring of coolant flow, pressure, and gas temperature at the intercooler outlet provides accurate operating data for the system and is the basis for precise temperature control; The controller, based on real-time temperature signals, controls the target temperature of the thermostatic heater, adjusts the PID proportional valve opening, and implements a multivariable coordinated control strategy to achieve precise control of the internal circulating water temperature. This control is achieved by combining the bypass valve's flow distribution with real-time temperature signals from the flow meter and temperature and pressure sensors. This control achieves precise control of the internal circulating water temperature by controlling the target temperature of the thermostatic heater, adjusting the opening of the PID proportional valve, and implementing a multivariable coordinated control strategy. Furthermore, the bypass valve's flow distribution adjustment allows for precise regulation of the intercooler outlet gas temperature.

[0031] In a preferred embodiment of the present invention, a filter element and a filter screen are respectively installed at the water inlet of the plate heat exchanger and the external circulation pipeline to ensure the cleanliness of the circulating medium. The filter element is precisely installed at the water inlet of the plate heat exchanger, effectively intercepting any particulate impurities in the coolant, preventing them from entering the heat exchanger and affecting heat exchange efficiency. The filter screen is installed in the external circulation pipeline to filter the externally circulating chilled water and prevent impurities from entering the system with the water flow. The two work together to comprehensively purify the circulating medium, effectively reducing the risk of impurities entering the intercooler and plate heat exchanger, ensuring the cleanliness of the circulating medium at the source, and ensuring the long-term stable and efficient operation of the system.

[0032] In the present invention, reference is made to Figure 1As shown in the figure, the starting end of the outer circulation pipeline is connected to the 7°C chilled water source. After preliminary impurity filtration through the filter element, it is successively connected to the PID proportional valve and the outer circulation side of the plate heat exchanger. Finally, the chilled water is discharged or returned to the chilled water system according to the system requirements, forming a closed-loop circulation. This pipeline layout not only ensures the cleanliness of the chilled water but also dynamically adjusts the chilled water flow through the PID proportional valve, and cooperates with the plate heat exchanger to control the temperature of the inner circulation coolant, ensuring the stable operation of the system under different working conditions.

[0033] In the present invention, the inner circulation loop is the core channel for precisely controlling the temperature of the intercooler, and its structural design and component layout are precisely planned. This loop is successively connected in series by the outlet end of the electronic water pump, the flow meter, the inlet / outlet ends of the intercooler, the constant temperature heater, the inlet / outlet of the inner circulation side of the plate heat exchanger, the filter screen, and the inlet end of the electronic water pump, forming a closed-loop circulation path, that is: outlet end of the electronic water pump → flow meter → inlet end of the engine intercooler → outlet end of the intercooler → constant temperature heater → inlet of the inner circulation side of the plate heat exchanger → filter screen → outlet of the inner circulation side of the plate heat exchanger → inlet end of the electronic water pump. In this circulation system, the electronic water pump drives the coolant to circulate, and the flow meter monitors the flow data in real time; the coolant after heat exchange in the intercooler is temperature-adjusted by the constant temperature heater and then undergoes heat exchange with the outer circulation chilled water through the plate heat exchanger. In addition, a throttle valve is configured in the bypass pipeline of the water pump, which can accurately adjust the flow and pressure of the inner circulation according to the system operation requirements, ensuring the stable flow of the coolant in the loop and laying a foundation for accurately controlling the outlet gas temperature of the intercooler.

[0034] In the present invention, the expansion water tank is connected to the pipeline node between the outlet end of the intercooler and the constant temperature heater through a three-way valve, forming a key hub for dynamic pressure regulation. When the coolant in the system expands due to heat or fluctuates in pressure, the expansion water tank can automatically absorb the excess liquid to prevent the pipeline pressure from being too high; when the system pressure decreases or the coolant is consumed, it can replenish the liquid in time to ensure that the pressure of the circulation loop is always maintained within a stable range. This connection method not only effectively balances the system pressure but also provides a buffer space for the thermal expansion and contraction of the coolant, ensuring the safe and stable operation of the entire temperature control system.

[0035] In the present invention, the temperature control process is as follows: Temperature target setting: Set the target temperature (T_target) of the outlet gas of the intercooler according to the test requirements.

[0036] Dynamic adjustment strategy: Heating stage (T_measured < T_target): When the measured temperature is lower than the target temperature, the system immediately starts the heating program: the outer circulation proportional valve is closed, and the constant temperature heater works to heat the coolant to the set temperature (such as 45°C). The electronic water pump adjusts the speed according to the preset flow curve to ensure that the high-temperature coolant fully flows through the intercooler to achieve rapid heating of the gas.

[0037] Cooling stage (T_measured > T_target): If the measured temperature is higher than the target temperature, the system enters cooling mode: the external loop PID proportional valve adjusts its opening according to the control algorithm, and the internal loop coolant temperature is reduced through the plate heat exchanger; the electronic water pump and bypass valve cooperate to adjust the internal loop flow rate to ensure that the heat exchange efficiency of the low-temperature coolant in the intercooler is maximized.

[0038] Constant temperature stage (T_measured ≈ T_target): When the measured temperature is close to the target temperature, the heating and cooling power are balanced through the multivariable collaborative control algorithm to maintain the temperature fluctuation range ≤±0.5℃.

[0039] PID algorithm optimization: Adaptive PID parameter adjustment: the controller monitors the system dynamic characteristics (such as temperature change rate, deviation) in real time and automatically adjusts the proportional (Kp), integral (Ki), and differential (Kd) parameters.

[0040] During engine startup or when the temperature changes rapidly, Kp is increased to improve response speed and Ki is reduced to avoid integral windup. When the temperature approaches the set point, Kp is reduced and Ki is increased to suppress overshoot and eliminate steady-state error. The adaptive PID algorithm can improve temperature control accuracy to ±0.5°C.

[0041] Fuzzy-PID composite control: A fuzzy control rule base is introduced to map the temperature deviation (e) and the deviation change rate (Δe) into fuzzy quantities, and dynamically correct the PID parameters.

[0042] When |e| > 2°C, the fuzzy controller takes control, quickly reducing the deviation. When |e| < 1°C, it switches to PID precise control mode. Comparative tests show that this algorithm reduces system response time by 25%-30% and improves anti-interference capabilities by 40%.

[0043] Multivariable collaborative control: Multi-parameter decoupling control: Establish a mathematical model with temperature (T), internal circulation pressure (P), and coolant flow (Q) as state variables, design a decoupling controller, achieve dynamic balance among the three parameters of temperature, pressure, and flow, eliminate the coupling effect between variables, and improve system control performance:

[0044] Among them, u1 and u2 correspond to the electronic water pump speed and PID proportional valve opening instructions respectively, achieving a dynamic balance between temperature, pressure and flow.

[0045] Predictive control algorithm: Builds an ARIMA forecasting model based on historical data to predict temperature trends 5-10 seconds in advance and generate feedforward control instructions. When the temperature is predicted to exceed the set point, the external circulation chilled water flow rate is increased in advance. When engine operating conditions suddenly change (such as a sudden load increase), the heater power and bypass valve opening are synchronously adjusted to suppress temperature fluctuations. Simulation results show that predictive control can reduce steady-state fluctuations by 60%.

[0046] Cleanliness guarantee: Double filtration by internal circulation filter and external circulation filter element prevents impurities from entering the intercooler and plate heat exchanger.

[0047] In the present invention, the control logic flow is specifically as follows: Water flow regulation, monitoring of water flow meter signals: distribution control of water system flow is achieved through control of the bypass valve, monitoring of water flow meter signals: synchronous control of the operating frequency of the electronic water pump, thereby fine-tuning the water pressure and the total flow of the water system; that is, the system collects water flow meter signals in real time to build a two-dimensional flow control mechanism: first, dynamically adjust the bypass valve opening based on flow data, accurately distribute the flow distribution of the internal circulation water channel, and ensure that the coolant flows through the intercooler and plate heat exchanger along the optimal path; second, synchronously monitor the water flow meter feedback signal, perform closed-loop control of the operating frequency of the electronic water pump according to the preset flow threshold, and achieve fine-tuning of the water pressure and the total flow of the system by adjusting the water pump speed to avoid the impact of flow fluctuations on heat exchange efficiency.

[0048] Temperature control, based on the temperature signal from the gas temperature sensor, controls the internal circulation water temperature by controlling the target temperature of the thermostatic heater and the PID proportional valve in conjunction with multivariable collaborative control. The gas temperature is controlled by utilizing the internal circulation water temperature for heat exchange within the vehicle's intercooler, combined with the bypass valve to adjust the water flow distribution. Specifically, a multi-level temperature control system is constructed with the real-time monitoring data of the intercooler outlet gas temperature sensor as the core control basis. First, the controller instructs the thermostatic heater to set the target temperature based on the temperature deviation, and accurately adjusts the external circulation chilled water flow through the PID proportional valve to achieve preliminary control of the internal circulation coolant temperature. At the same time, a multivariable collaborative control algorithm is introduced to incorporate parameters such as the internal circulation pressure and coolant flow into the control model. The heat exchange efficiency of the coolant in the intercooler is optimized by dynamically adjusting the electronic water pump speed and the bypass valve opening. Finally, the heat exchange process between the internal circulation coolant and the gas in the intercooler is utilized, combined with the secondary adjustment of the water flow distribution by the bypass valve, to achieve precise control of the intercooler outlet gas temperature.

[0049] Safety failure monitoring monitors water flow / adds pressure measurement points to the water flow meter to determine the operating status of the electronic water pump. When there is no flow / pressure, the operating system is triggered to alarm. Furthermore, pressure measurement devices are added at key nodes of the water flow meter to establish a dual safety monitoring mechanism: the system continuously monitors water flow and pressure data, and determines the operating status of the electronic water pump based on preset thresholds. When abnormal operating conditions such as no flow output or a sudden drop in pressure occur, the system immediately triggers the linkage alarm mechanism, sending an audible and visual alarm signal to the operation interface and simultaneously generating a fault diagnosis report, detailing information such as the abnormal time and parameter fluctuation range. This provides comprehensive data support for equipment maintenance and troubleshooting, ensuring a safe and controllable test process.

[0050] This system achieves a highly realistic test environment by directly utilizing the vehicle's original intercooler as a core component, maximizing the reproduction of pressure and flow characteristics under realistic operating conditions. Compared to traditional testing equipment, this system ensures that test data closely matches actual vehicle operating conditions, providing more valuable test results for engine performance research and development, significantly improving test simulation accuracy.

[0051] High-Precision Temperature Control: Integrating a PID algorithm with dual-loop control technology, the system precisely regulates the intercooler outlet gas temperature. Field-proven temperature control accuracy reaches ±0.5°C. Compared to traditional single-loop temperature control systems, this system more stably and accurately simulates engine temperature changes under various operating conditions, meeting the stringent requirements of high-fidelity testing.

[0052] Excellent dynamic response performance: Through a multivariable coordinated control strategy, the system response time is significantly reduced to less than 3 seconds, enabling rapid response to sudden changes in engine operating conditions. Furthermore, an adaptive algorithm automatically optimizes control parameters based on the system's operating status, effectively reducing manual debugging workload and significantly improving the system's intelligence, enabling it to maintain stable operation even under complex dynamic conditions.

[0053] High reliability and long life design: A multi-stage filtration solution with internal and external filter elements effectively traps impurities in the circulating medium, preventing pipe blockage and equipment wear. This design not only improves system reliability but also extends the service life of core components such as the intercooler and plate heat exchanger, reducing maintenance frequency.

[0054] Low-cost and convenient maintenance: The system utilizes a modular design, allowing each functional component to be independently disassembled, assembled, and replaced, significantly reducing repair time. Furthermore, a bypass proportional valve optimizes the coolant circulation path, effectively reducing the load on the electronic water pump. This achieves energy savings and consumption reductions while maintaining system performance, significantly reducing the overall equipment lifecycle cost.

[0055] Reference Figure 1 As shown, the system of the present invention specifically includes: In the external circulation, the chilled water source acts as the starting point for the cold source, providing low-temperature chilled water. The filter element filters the chilled water entering the system, intercepting impurities to ensure water cleanliness and prevent clogging of components such as the plate heat exchanger.

[0056] PID proportional valve: Adjusts its opening according to a control algorithm, precisely controlling the flow of chilled water into the plate heat exchanger. When the system needs to cool, the valve opens wider to introduce more chilled water. During warming or constant temperature phases, the valve opens narrower or closes to precisely adjust the heat exchange intensity. The plate heat exchanger (plate heat exchanger) is the core component that exchanges heat between the external and internal coolant loops. Through the plate heat exchanger, the external chilled water removes heat from the internal coolant, cooling it and thereby regulating the gas temperature within the intercooler.

[0057] In the internal circulation, the filter further filters impurities from the internal coolant, preventing them from entering key components such as the thermostatic heater and electronic water pump, thereby preventing wear and malfunction caused by impurities. The thermostatic heater operates according to system temperature requirements. During the warm-up phase, it heats the internal coolant to a set temperature (e.g., 45°C), providing high-temperature coolant to the intercooler and heating the air inside the intercooler. The three-way valve connects to the expansion tank and balances the pressure in the internal circulation system. As the coolant expands due to heat, excess coolant flows into the expansion tank. When system pressure drops or coolant is depleted, coolant in the expansion tank flows back to replenish the system pressure, maintaining a stable system pressure. The electronic water pump provides power for the internal coolant circulation and adjusts its speed according to system control commands (such as preset flow curves and multivariable coordinated control algorithm commands). It precisely controls the coolant flow rate and velocity, ensuring that the coolant circulates within the system according to the designed path and flow requirements. The bypass valve works in conjunction with the electronic water pump to control the coolant diversion ratio by adjusting the opening. When the temperature rises, reduce the opening to allow more coolant to flow through the intercooler; when the temperature drops, increase the opening to increase the coolant circulation volume and optimize the heat exchange efficiency in the intercooler.

[0058] Flow meter: monitors the internal circulation coolant flow in real time and feeds the flow signal back to the control system as one of the bases for adjusting the electronic water pump speed and bypass valve opening to ensure that the system flow meets the set requirements.

[0059] Regarding the gas, the vehicle's intercooler is where heat exchange occurs between the gas and the internal coolant. The internal coolant flows through the intercooler, exchanging heat with the intercooler's intake air, regulating the intercooler's outlet temperature to meet the engine's intake air temperature requirements. A gas temperature sensor, installed at the intercooler outlet, monitors the intercooler's outlet temperature in real time and feeds the temperature signal back to the control system. Based on this temperature signal and the target temperature setpoint, the control system adjusts components such as the external circulation PID proportional valve, thermostatic heater, electronic water pump, and bypass valve to precisely control the intercooler's outlet gas temperature.

[0060] Example 1, with reference to Figure 1 As shown, the system startup process When the system starts, the electronic water pump is first turned on, and the internal circulation coolant flow rate is set to the test demand value (50L / min, for example) to provide power for the entire circulation system. Simultaneously, the initial temperature of the thermostatic heater is set to 45°C to prepare for possible subsequent temperature increases. At this point, the external circulation proportional valve is closed, cutting off the external circulation chilled water path. This prevents the cold source from interfering with the initial temperature control and ensures a smooth system startup from the preset initial state.

[0061] Temperature control implementation: When the system detects that the intercooler outlet gas temperature is below the target, the temperature increase mechanism is immediately triggered: the thermostatic heater continues to operate to maintain the internal coolant temperature at the set temperature. Simultaneously, the bypass valve is opened narrowly, limiting the coolant bypass flow and allowing more high-temperature coolant to flow through the intercooler. The electronic water pump, in conjunction with the bypass valve, increases its speed according to a preset flow curve, ensuring that the high-temperature coolant enters the intercooler at the optimal flow rate and volume, accelerating the gas temperature increase until the measured temperature reaches the target value.

[0062] During cooling control, if the intercooler outlet gas temperature exceeds the target, the system rapidly enters cooling mode. The external loop PID proportional valve gradually increases its opening according to the control algorithm, introducing more 7°C chilled water into the plate heat exchanger and enhancing heat exchange efficiency between the external and internal coolants. Simultaneously, the bypass valve opens wider, increasing the internal coolant flow rate and allowing more low-temperature coolant to flow through the intercooler. The electronic water pump simultaneously adjusts its speed to optimize the coolant circulation rate, ensuring sufficient heat exchange within the intercooler and achieving rapid cooling until the gas temperature returns to the target range.

[0063] Example 2, an engine test bench intercooler temperature control system, specifically comprising: Intercooler: The original intercooler of the vehicle is selected, and its structure and parameters are consistent with the actual vehicle configuration, ensuring that the test can highly simulate the real working scenario and guarantee the accuracy and reference of the data.

[0064] Constant temperature heater: uses a high-precision electric heating element to heat the coolant to a preset temperature within a range of 25-70°C. It has multiple safety protection mechanisms, including overheat protection and leakage protection.

[0065] Electronic water pump: A PWM variable frequency pump is used, which can accurately adjust the speed according to system instructions to provide power for coolant circulation. It can achieve precise control of coolant flow.

[0066] Plate heat exchanger (plate heat exchanger): adopts a high-efficiency and compact design. It exchanges heat with the internal circulating coolant through the external circulating 7℃ chilled water, achieving the cooling of the internal circulating coolant.

[0067] Expansion kettle: connected to the circulation system through a three-way valve, it can accommodate excess liquid when the coolant expands due to heat, replenish coolant when the system pressure drops, achieve water replenishment and pressure balance, and maintain stable system pressure.

[0068] Bypass valve and PID proportional valve: The bypass valve is installed in the water pump bypass line, with an opening adjustment range of 0-100%, for dynamically adjusting the coolant diversion ratio. The PID proportional valve is installed in the external circulation chilled water pipeline to accurately adjust the external circulation chilled water flow according to the control algorithm.

[0069] Flow meter and temperature pressure sensor, the flow meter uses electromagnetic flow meter to monitor the coolant flow in real time.

[0070] The temperature sensor uses a platinum resistance temperature sensor, which is arranged at key locations such as the intercooler inlet and outlet, coolant pipeline, etc. to monitor the temperature in real time.

[0071] The pressure sensor monitors the coolant line pressure.

[0072] Controller: Utilizing a high-performance industrial-grade microprocessor with a wide range of interfaces (such as CAN, RS485, GPIO, etc.) for data acquisition, processing, and control command output. Equipped with multiple built-in control algorithms and intelligent models, it serves as the system's core control unit.

[0073] Intelligent working condition adaptation, in this embodiment, a working condition identification module is added; Multiple high-precision sensors are installed: the engine speed sensor has an accuracy of ±1r / min, the throttle opening sensor has an accuracy of ±0.5%, and the intake air flow sensor has an accuracy of ±1%, to collect engine operating parameters in real time.

[0074] Improved deep learning algorithms (such as those based on a model combining a convolutional neural network (CNN) and a long short-term memory (LSTM) network) are used to perform in-depth analysis and classification of collected parameters. CNN extracts spatial features from the parameters, while LSTM processes time series features, accurately identifying the engine's current operating condition, such as idling, light-load acceleration, heavy-load acceleration, constant speed driving, and deceleration. The accuracy of operating condition identification exceeds 98%.

[0075] A detailed and continuously updated operating condition-parameter mapping database, established through extensive testing and simulation analysis, records the optimal intercooler temperature control parameter combinations under different operating conditions, including the thermostatic heater target temperature, electronic water pump speed, PID proportional valve opening, and bypass valve opening.

[0076] After the operating condition identification module determines the current operating condition, the controller retrieves the corresponding parameter combination from the database as the initial control parameters.

[0077] Adaptive adjustment mechanism: During actual operation, the controller monitors the deviation between the intercooler outlet gas temperature and the target temperature in real time at a frequency of 100ms.

[0078] An adaptive fuzzy logic control algorithm dynamically adjusts control parameters based on temperature deviation and the rate of change of that deviation. The fuzzy logic rule base is built from extensive test data and expert experience and continuously optimized through online learning. For example, when both the temperature deviation and the rate of change are large, the system rapidly increases the power of the thermostatic heater or adjusts the bypass valve opening. When the temperature approaches the target value, the control parameters are fine-tuned to achieve precise control.

[0079] The control algorithm is integrated, reinforcement learning is integrated with PID control, and a deep reinforcement learning algorithm improved based on the deep Q network (DQN) is introduced. The state space is defined as real-time monitoring parameters such as intercooler outlet gas temperature, coolant flow, pressure, and engine operating conditions; the action space is control variables such as constant temperature heater power adjustment, electronic water pump speed adjustment, and PID proportional valve opening adjustment.

[0080] In the early stages of the system's operation, the reinforcement learning agent accumulates experience data through random exploration and interaction with the environment. As the system runs longer, it uses experience replay and deep neural network training to learn the optimal control strategy. Simultaneously, a traditional PID controller, serving as the foundational control algorithm, provides stable control outputs with a 50ms cycle during the reinforcement learning agent's learning process, ensuring basic system stability during the learning phase.

[0081] Once the reinforcement learning agent has learned an effective control strategy, it is integrated with the PID controller. Based on different operating conditions and system states, an adaptive weight adjustment mechanism dynamically adjusts the weights of reinforcement learning and PID control. For example, when operating conditions change rapidly, the reinforcement learning weight increases to quickly adapt to the new conditions; when operating conditions stabilize, the PID control weight increases to achieve precise fine-tuning control.

[0082] By integrating model predictive control (MPC) with fuzzy control, and based on the system's physical model and historical operating data, we employ an autoregressive integrated moving average (ARIMA) algorithm combined with an artificial neural network (ANN) to establish a high-precision prediction model for intercooler temperature control. ARIMA captures the linear characteristics of the time series, while the ANN learns the nonlinear characteristics, enabling accurate predictions of temperature trends over the next 5-10 seconds.

[0083] Based on the prediction results, the model predictive control algorithm (MPC) calculates the optimal control sequence for a period of time in the future with a cycle of 200ms, taking into account system constraints (such as component power limitations, flow limitations, etc.) to make the system state as close to the target state as possible.

[0084] A fuzzy control rule base was introduced to modify the control sequence calculated by the MPC based on temperature deviation and the rate of change of the deviation. This rule base was optimized using extensive simulation and experimental data. When the temperature deviation exceeds 2°C, the fuzzy controller takes control, rapidly adjusting control parameters to minimize the deviation. When the temperature deviation is less than 1°C, the MPC algorithm takes primary responsibility, achieving precise control and ensuring the temperature remains stable near the target value.

[0085] System workflow: After the system is started and powered on, the controller initializes the parameters of each component. The electronic water pump is turned on and the flow rate of the internal circulation coolant is set to the test requirement value.

[0086] The thermostatic heater is initially set to 45°C, and the external circulation proportional valve is closed. The system performs a self-test to check whether all sensors, actuators, and communication links are functioning properly. If any abnormality is found, an alarm is issued and the startup is stopped.

[0087] The operating condition identification module collects engine operating parameters in real time at a frequency of 100ms. It uses a deep learning model to identify the operating condition and transmits the identification results to the controller.

[0088] Based on the working condition identification results, the controller retrieves the corresponding initial control parameters from the working condition-parameter mapping database, completes parameter loading, and sends control instructions to each actuator.

[0089] For temperature control, the controller dynamically adjusts the control parameters at a frequency of 100ms based on the deviation between the real-time monitored intercooler outlet gas temperature and the target temperature, using a fusion of new control algorithms (reinforcement learning and PID fusion, MPC and fuzzy control fusion).

[0090] During the heating phase (measured): The external circulation proportional valve remains closed, and the thermostatic heater adjusts its power with an accuracy of ±0.1kW based on control commands to heat the coolant. The bypass valve decreases its opening with an accuracy of ±0.5%, increasing coolant flow through the intercooler. The electronic water pump adjusts its speed with an accuracy of ±1r / min based on flow demand.

[0091] During the cooling phase (measured): The external loop PID proportional valve adjusts its opening with a ±0.5% accuracy based on the control algorithm, introducing more 7°C chilled water into the plate heat exchanger and improving heat exchange efficiency. The bypass valve opens wider with a ±0.5% accuracy, increasing coolant flow through the intercooler. The electronic water pump simultaneously adjusts its speed to ensure coolant circulation meets cooling requirements.

[0092] Constant Temperature Phase (Measured): A multivariable collaborative control algorithm balances heating and cooling power with a 100ms cycle. Reinforcement learning, PID fusion, and MPC and fuzzy control fusion algorithms work together to maintain a temperature fluctuation range of ≤±0.5°C.

[0093] For safety monitoring and troubleshooting, the system monitors water flow and pressure in real time at a frequency of 50ms. When the flow rate falls below a set threshold (e.g., 80% of normal flow) or the pressure is abnormal, the system triggers an audible and visual alarm and records the fault time, parameters, and other information within 100ms.

[0094] If a system component fails, such as an electronic water pump failure (determined by monitoring abnormal speed, excessive current, etc.) or a constant temperature heater failure (determined by abnormal temperature, abnormal power output), the controller automatically switches to the backup component within 200ms and uploads the fault information to the remote monitoring platform. At the same time, detailed fault information is recorded for maintenance personnel to analyze and troubleshoot.

[0095] In this embodiment, intelligent operating condition adaptation: accurate and rapid identification of operating conditions is achieved through high-precision sensors and advanced deep learning algorithms. The distributed storage and rapid retrieval of the operating condition-parameter mapping database, as well as the adaptive fuzzy logic adjustment mechanism, enable the system to quickly find and adjust to the optimal control parameters under different operating conditions, significantly improving the accuracy and response speed of temperature control. Compared with traditional systems, the response speed is increased by more than 50%, and the operating condition adaptability is improved by more than 30%. New control algorithm fusion: The innovative fusion of reinforcement learning and PID control, MPC and fuzzy control, fully leverages the advantages of each algorithm. Reinforcement learning enables autonomous learning and optimized control of complex operating conditions, while PID ensures basic stability; MPC performs forward-looking control based on predictions, and fuzzy control handles nonlinearity and uncertainty. The fusion algorithm improves temperature control accuracy to within ±0.5°C, improves the system's anti-interference ability by more than 40%, and shortens response time by more than 30%.

[0096] High-Precision Temperature Control: From high-precision hardware sensors and actuators to intelligent algorithms, the system ensures precise control of intercooler outlet gas temperature. The system maintains stable temperature within ±0.5°C under various operating and environmental conditions, meeting the stringent temperature control requirements of high-simulation engine testing. Reliability and Safety: Redundant design of key components, multiple safety protection mechanisms, and real-time fault monitoring and handling ensure reliable system operation under various circumstances. Fast failover time and detailed fault information logging improve system availability and maintainability, reducing the risk of test interruption and maintenance costs.

[0097] The technical principles of the present invention have been described above in conjunction with specific embodiments, which are merely preferred embodiments of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions based on the principles of the present invention fall within the scope of protection of the present invention. Those skilled in the art will be able to conceive of other specific embodiments of the present invention without inventive effort, and such methods will fall within the scope of protection of the present invention.

Claims

1. An engine test bench intercooler temperature control system, characterized in that: It includes an intercooler to simulate the working conditions under actual working conditions; a constant temperature heater to heat the coolant to the preset temperature; an electronic water pump to drive the coolant circulation with controllable flow; and a plate heat exchanger for heat exchange between the external circulating chilled water and the internal circulating coolant. The expansion kettle is connected to the circulation system through a three-way valve to achieve water replenishment and pressure balance; the bypass valve and PID proportional valve, the bypass valve is set in the water pump bypass line to adjust the internal circulation flow and pressure, and the PID proportional valve is set in the external circulation chilled water line to dynamically adjust the external circulation chilled water flow; the flow meter and temperature and pressure sensor monitor the coolant flow, pressure and intercooler outlet gas temperature in real time; the controller, based on the real-time monitored temperature signal, controls the target temperature of the thermostatic heater and the PID proportional valve and multivariable collaborative control to achieve internal circulation water temperature control, and combines the bypass valve to adjust the water flow distribution to achieve gas temperature control.

2. The engine test bench intercooler temperature control system according to claim 1, characterized in that: The electronic water pump is a PWM variable frequency pump.

3. The engine test bench intercooler temperature control system according to claim 1, characterized in that: It also includes filter elements and filter screens, which are respectively arranged at the water inlet of the plate heat exchanger and the external circulation pipeline to ensure the cleanliness of the circulating medium.

4. The engine test bench intercooler temperature control system according to claim 2, characterized in that: The external circulation pipeline is connected in sequence to the chilled water source, filter element, PID proportional valve, external circulation side of the plate heat exchanger, and discharged or returned to the chilled water system.

5. The engine test bench intercooler temperature control system according to claim 3, characterized in that: The electronic water pump outlet, flow meter, intercooler water inlet, intercooler water outlet, constant temperature heater, plate heat exchanger internal circulation side water inlet, filter, plate heat exchanger internal circulation side water outlet, and electronic water pump water inlet connected in sequence constitute an internal circulation loop.

6. The engine test bench intercooler temperature control system according to claim 1, characterized in that: The expansion kettle is connected between the water outlet of the intercooler and the constant temperature heater through a three-way valve.

7. The engine test bench intercooler temperature control system according to claim 1, characterized in that: The temperature control process includes: temperature target setting: setting the target intercooler outlet gas temperature based on test requirements; dynamic adjustment strategy: during the heating phase, the external loop PID proportional valve is closed, the thermostatic heater operates, and the electronic water pump adjusts its speed according to a preset flow curve; during the cooling phase, the external loop PID proportional valve adjusts its opening according to the control algorithm, and the electronic water pump and bypass valve coordinately regulate the internal loop flow; during the constant temperature phase, a multivariable collaborative control algorithm is used to balance heating and cooling power; PID algorithm optimization: adaptive PID parameter adjustment: the controller monitors the system's dynamic characteristics in real time and automatically adjusts the proportional, integral, and differential parameters; fuzzy-PID compound control: a fuzzy control rule library is introduced to dynamically modify the PID parameters based on temperature deviation and the rate of change of the deviation; multivariable collaborative control: multi-parameter decoupling control: a mathematical model with temperature, internal loop pressure, and coolant flow as state variables is established, and a decoupling controller is designed; a predictive control algorithm: an ARIMA prediction model is constructed based on historical data to predict temperature trends and generate feedforward control instructions; cleanliness assurance: dual filtration of the internal and external loop filters prevents impurities from entering the intercooler and plate heat exchanger.

8. The engine test bench intercooler temperature control system according to claim 7, characterized in that: By monitoring the water flow meter signal and controlling the bypass valve, the water system flow distribution is controlled. At the same time, the operating frequency of the electronic water pump is controlled to fine-tune the water pressure and the total flow of the water system. A pressure measurement point is added at the water flow meter to determine the working status of the electronic water pump based on the flow and pressure. When there is no flow / pressure, the operating system is linked to the alarm.

9. The engine test bench intercooler temperature control system according to claim 8, characterized in that: The introduction of the fuzzy control rule base specifically includes mapping the temperature deviation (e) and the deviation change rate (Δe) into fuzzy quantities and dynamically correcting the PID parameters. When |e|>2°C, the fuzzy controller takes the lead in regulation to quickly reduce the deviation; when |e|<1°C, it switches to the PID precise control mode.

10. The engine test bench intercooler temperature control system according to claim 8, characterized in that: The multi-parameter decoupling control specifically includes establishing a mathematical model with temperature (T), internal circulation pressure (P), and coolant flow (Q) as state variables, and designing a decoupling controller: , where u1 and u2 correspond to the electronic water pump speed and PID proportional valve opening instructions respectively, to achieve the dynamic balance of temperature-pressure-flow, T arget is the target temperature of the intercooler outlet gas.

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