Automobile intelligent temperature control system and control method based on vortex tube and electronic expansion valve

Abstract

The application discloses a kind of based on vortex tube and electronic expansion valve's automobile intelligent temperature control system and control method, comprising: vortex tube, the vortex tube has cold end outlet, hot end outlet and high-pressure inlet;Compressor unit is connected with high-pressure inlet and high-pressure gas is sent into vortex tube, further comprising: electronic expansion valve control module, along the axial of vortex tube and the hot end outlet of vortex tube is connected, the flow of hot end outlet is adjusted by the valve port of electronic expansion valve;Distributed sensor group, at least including pressure sensor, temperature sensor and flow sensor, distribute in cold end outlet and / or hot end outlet and / or high-pressure inlet;Intelligent control unit is electrically connected with compressor unit, electronic expansion valve control module and distributed sensor group.The electronic expansion valve of the present application is integrated with multistage vortex tube array, can solve the problem of low adjustment accuracy, response lag, short service life in prior art mechanical screw adjustment scheme.

Description

Technical Field

[0001] This invention relates to the field of thermal management technology for new energy vehicles, specifically to an intelligent temperature control system and control method for automobiles based on vortex tubes and electronic expansion valves. Background Technology

[0002] Multi-stage vortex tube arrays play a crucial role in automotive temperature control systems. Compressed gas enters the vortex tube through the inlet and, guided by a double-helix counter-flow channel, undergoes high-speed spiral motion. Due to friction and collisions between gas molecules, the gas's kinetic energy is converted into heat energy. Inside the vortex tube, the gas is divided into two parts with different temperatures: the central part, with a lower temperature, flows out from the cold end outlet; the outer part, with a higher temperature, flows out from the hot end outlet.

[0003] Traditional eddy current tube hot-end temperature control relies on mechanical adjusting screws, which has the following drawbacks:

[0004] 1. Low adjustment precision: The screw pitch is typically 0.5–1 mm, and a single rotation can only achieve sub-millimeter level displacement, while the flow rate adjustment at the hot end of the vortex tube requires micrometer-level opening changes (e.g., valve orifice flow area of ​​0.05–2.5 mm). 2 Manual operation is limited by the precision of finger force control (minimum discernible displacement > 50μm), resulting in an actual opening control error > 10%, causing cold end temperature fluctuations of ±2℃ (e.g., when the target temperature is 25℃, the actual temperature oscillates between 23 and 27℃). Cooling of power batteries for new energy vehicles requires precise ultra-low temperature control of -40℃ ± 0.2℃. Temperature drift in traditional solutions will lead to accelerated degradation of battery active materials (shortening lifespan by more than 30%). Electronic equipment requires heat dissipation of 25℃ ± 0.5℃; exceeding the temperature limit will cause malfunctions such as CPU frequency reduction and chip solder joint failure.

[0005] 2. Response lag: The eddy tube temperature control system needs to respond in real time to dynamic operating conditions such as compressor start-stop, vehicle acceleration and deceleration, and sudden changes in ambient temperature (temperature change rate > 3℃ / s). However, mechanical adjustment has three lags: First, there is an operational delay. After manually sensing the temperature deviation, it is necessary to stop the vehicle, locate the screw, and tighten it. The total response time is > 5 seconds, which is much longer than the cycle of operating condition changes (such as the cycle of airflow parameter changes during rapid acceleration < 1 second). Second, there is mechanical inertia. There is a backlash (> 50μm) between the screw and the valve seat thread pair, and the adjustment process needs to overcome friction (static friction coefficient > 0.3), resulting in an opening adjustment rate < 0.1mm / s. It is impossible to suppress temperature overshoot in time. Taking the sudden heat dissipation demand of electronic equipment during high-speed driving as an example, the traditional solution causes the equipment temperature to rise sharply to 80℃ (exceeding the safety threshold of 70℃) due to the response lag, and then slowly drop back. Over time, this will cause thermal fatigue cracking of the circuit board solder joints.

[0006] 3. Short lifespan: The vehicle environment is subject to high-frequency vibration (5-200Hz, acceleration >5g) and temperature fluctuations (-40℃ to 85℃), which can lead to fatal failures in the mechanical adjustment structure. The threaded pair (usually made of stainless steel / copper alloy) undergoes micro-displacement during vibration, resulting in adhesive wear and abrasive wear on the contact surface. After 5000 cumulative adjustments, the pitch error exceeds 5%, leading to uncontrolled opening (e.g., the target opening is 20%, but the actual opening reaches 25%). Traditional solutions require maintenance cycles of less than 6 months, necessitating the disassembly of the eddy current tube assembly and screw replacement. A single maintenance at a new energy vehicle after-sales service center takes more than 2 hours and costs more than 500 yuan. The risk of threaded pair breakage (especially under 21Bar high-pressure air source vibration conditions) may cause hot-end airflow leakage, with high-temperature gas (127℃) being sprayed onto the cabin or circuit board, posing a risk of burns and short circuits.

[0007] Existing technologies (such as patent CN113587123A) attempt to use electromagnetic valves for regulation, but they are not optimized for the flow field characteristics of the hot end of the vortex tube, resulting in large airflow disturbances and poor control linearity (error > ±1.5℃). Summary of the Invention

[0008] This invention provides an intelligent automotive temperature control system and control method based on vortex tubes and electronic expansion valves. By deeply integrating the electronic expansion valve with a multi-stage vortex tube array, it can solve the problems of low adjustment accuracy, slow response, and short lifespan of existing mechanical screw adjustment schemes.

[0009] To achieve the above objectives, in a first aspect, the present invention provides the following technical solution: an intelligent automotive temperature control system based on a vortex tube and an electronic expansion valve, comprising: a vortex tube having a cold end outlet, a hot end outlet, and a high-pressure inlet; a compressor unit connected to the high-pressure inlet and supplying high-pressure gas into the vortex tube; further comprising: an electronic expansion valve control module connected along the axial direction of the vortex tube to the hot end outlet of the vortex tube, adjusting the flow rate at the hot end outlet through the valve port of the electronic expansion valve; a distributed sensor group, including at least a pressure sensor, a temperature sensor, and a flow sensor, distributed at the cold end outlet and / or the hot end outlet and / or the high-pressure inlet; and an intelligent control unit electrically connected to the compressor unit, the electronic expansion valve control module, and the distributed sensor group, wherein the intelligent control unit is configured to perform the following operations:

[0010] A. Based on the intake pressure-temperature transfer model: ΔT=8.5*ln(P / 21)+0.12*α 1.5 This generates an electronic expansion valve opening command, where P is the intake pressure, ΔT is the temperature change between the cold end outlet and the hot end outlet, and α is the opening degree of the electronic expansion valve.

[0011] B. The compressor unit and the electronic expansion valve control module are coordinated through a multivariable decoupling algorithm to suppress dynamic operating condition disturbances;

[0012] C. Achieve temperature control accuracy of ±0.2℃ at the cold end outlet and ±1℃ at the hot end outlet, and recover waste heat from the hot end for cabin heating.

[0013] The aforementioned technical solution utilizes a multivariable decoupling algorithm to coordinate the compressor and electronic expansion valve, suppressing gas source pulsation. The decoupled temperature control at the cold and hot ends achieves a temperature difference of 167℃. Based on the intake pressure-temperature transfer model, it can achieve precise control of ±0.2℃ at the cold end and ±1℃ at the hot end. Waste heat recovery at the hot end is used for cabin heating, resulting in a system energy efficiency ratio of 0.48, which is 42% more energy-efficient than traditional PTC solutions. The system simultaneously supports ultra-low temperature cooling of the power battery, constant temperature heat dissipation of electronic equipment, and cabin comfort adjustment. It maintains stable operation even under dynamic conditions such as compressor start-stop and vehicle vibration, providing a highly reliable and energy-efficient solution for new energy vehicles and industrial precision temperature control.

[0014] As a supplement, a two-stage pressure stabilization module is also included, which is set between the high-pressure inlet and the compressor unit. It includes a buffer tank and a sonic nozzle connected to the buffer tank. The buffer tank is equipped with a variable throttling component, which solves the problem that the fixed orifice plate in the traditional buffer tank cannot dynamically compensate for flow resistance. In addition, in conjunction with the sonic nozzle, it suppresses the air source pressure fluctuation to ±0.35%, providing a stable input for the multi-stage vortex tube array.

[0015] Preferably, the variable throttling assembly includes a fixed orifice plate with a flow hole and a movable orifice plate for controlling the flow area of ​​the flow hole. The movable orifice plate is driven by the actuator to slide along a direction perpendicular to the airflow. Through the cooperation of the movable orifice plate and the actuator, the variable throttling assembly can achieve precise and rapid response control. It can work in conjunction with the stepper motor control algorithm of the electronic expansion valve (both adopt position closed-loop control) and synchronize data through the CAN bus to ensure that the adjustment phase difference between the buffer tank and EXV is <10ms.

[0016] Preferably, the multivariate decoupling algorithm includes:

[0017] a. By predicting pressure fluctuations based on compressor speed and vehicle acceleration and adjusting the opening of the electronic expansion valve in advance, about 90% of predictable disturbances (such as compressor start-stop, vehicle acceleration and deceleration) can be eliminated, with a response time of <0.2 seconds, which is more than 5 times faster than traditional feedback control.

[0018] b. The Lyapunov function is used to evaluate the system stability and automatically adjust the PID parameters to ensure that the overshoot at the cold end outlet is <0.5℃. Compared with fixed PID parameters, the control accuracy after dynamic optimization is improved by 3 times, which is especially suitable for scenarios such as power batteries that are sensitive to overshoot.

[0019] Preferably, the electronic expansion valve control module consists of a high-precision electronic expansion valve driven by a stepper motor. The stepper motor receives pulse signals from the intelligent control unit and converts these signals into angular or linear displacement, precisely driving the valve core to change the flow area at the valve orifice. The intelligent control unit calculates the required valve opening command based on the intake pressure-temperature transmission model, controls the stepper motor to precisely regulate the airflow and pressure at the hot end of the vortex tube, thereby controlling the temperature at both the hot and cold ends.

[0020] Preferably, a valve connector is axially connected to the hot end outlet, and the electronic expansion valve control module is connected to the valve connector. An air outlet is opened on the side wall of the valve connector, and the valve core of the electronic expansion valve control module is installed in the valve connector. This facilitates the installation of the electronic expansion valve control module at the axial end of the vortex tube, avoids airflow deflection, eliminates the need to modify the existing vortex tube, and reduces costs.

[0021] In a second aspect, the present invention also provides a control method for an automotive intelligent temperature control system based on a vortex tube and an electronic expansion valve according to the first aspect, comprising the following steps:

[0022] S1. Initialize the system and set the target cold end temperature T at the cold end outlet. c_target and the hot-end waste heat recovery threshold T at the hot-end outlet hmin ;

[0023] S2, Real-time acquisition of gas source pressure P through a distributed sensor array in Traffic Q in Cold junction temperature T c and hot end temperature T h；

[0024] S3. According to the model, ΔT = 8.5 * ln(P / 21) + 0.12 * α 1.5 Calculate the current valve opening α current ;

[0025] S4, if T c -T c_target If the temperature is greater than 0.5℃, fuzzy PID control will be activated to correct α. current To α new , where α new The corrected opening;

[0026] When T h >T hmin When the waste heat recovery is activated, press Q. heat =K·(T) h -T hmin Distribute hot-end flow, Q heatK is the proportional coefficient preset according to the system design, which is used to control the intensity of waste heat utilization and allocate the hot end flow rate to waste heat recovery.

[0027] Compared with the prior art, the beneficial effects of the present invention are:

[0028] By employing a multivariable decoupling algorithm to coordinate the compressor and electronic expansion valve, gas source pulsation is suppressed, achieving a temperature difference of 167℃ between the cold and hot ends through decoupling control. Based on the intake pressure-temperature transfer model, precise control of ±0.2℃ at the cold end and ±1℃ at the hot end can be achieved. Waste heat recovery at the hot end is used for cabin heating, resulting in a system energy efficiency ratio of 0.48, which is 42% more energy-efficient than traditional PTC solutions. The system simultaneously supports ultra-low temperature cooling of the power battery, constant temperature heat dissipation of electronic equipment, and cabin comfort adjustment. It maintains stable operation even under dynamic conditions such as compressor start-up and shutdown, and vehicle vibration, providing a highly reliable and energy-efficient solution for new energy vehicles and industrial precision temperature control. Attached Figure Description

[0029] Figure 1 This is an overall cross-sectional view of the present invention;

[0030] Figure 2 This is a schematic diagram of the control system of the present invention.

[0031] Figure label:

[0032] 1. Vortex tube; 11. High-pressure inlet; 12. Cold end outlet; 13. Air outlet; 2. Valve connector; 3. Electronic expansion valve control module; 4. Hot end outlet; 5. Valve core; 6. Sonic nozzle; 7. Buffer tank; 8. Compressor unit; 9. Intelligent control unit; 10. Distributed sensor group. Detailed Implementation

[0033] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0034] like Figure 1-2As shown, this invention provides a solution to address the problems of low adjustment accuracy, slow response, and short lifespan of existing mechanical screw adjustment schemes. The invention offers the following technical solution: an intelligent automotive temperature control system based on a vortex tube and an electronic expansion valve, comprising: a vortex tube 1 having a cold end outlet 12, a hot end outlet 4, and a high-pressure inlet 11; a compressor unit 8 connected to the high-pressure inlet 11 and supplying high-pressure gas into the vortex tube 1; an electronic expansion valve control module 3 connected along the axial direction of the vortex tube 1 to the hot end outlet 4, regulating the flow rate at the hot end outlet 4 via the valve port of the electronic expansion valve; a distributed sensor group 10, including at least a pressure sensor, a temperature sensor, and a flow sensor, distributed at the cold end outlet 12 and / or the hot end outlet 4 and / or the high-pressure inlet 11; and an intelligent control unit 9 electrically connected to the compressor unit 8, the electronic expansion valve control module 3, and the distributed sensor group 10.

[0035] Specifically, multiple vortex tubes 1 can be installed and used in parallel, with multiple vortex tubes 1 sharing one compressor unit 8. The vortex tube body is made of austenitic stainless steel (06Cr19Ni10), formed by laser welding, with a wall thickness of 1.5mm±0.1mm, ensuring structural strength and sealing. The internal flow channel is designed as a double-helix reverse flow channel with a helix angle of 32°±1° and a lead ratio of 1:5.5. This design enables the incoming compressed gas to form a strong spiral motion inside the tube. The flow channel surface is electrolytically polished, with a roughness Ra≤0.4μm, which reduces gas flow resistance. The compressed gas generated by the compressor unit 8 enters the vortex tube 1 through the high-pressure inlet 11 and forms a high-speed spiral motion under the guidance of the double-helix reverse flow channel. Due to the friction and collision between gas molecules, the kinetic energy of the gas is converted into heat energy. Inside the vortex tube, the gas is divided into two parts with different temperatures: the gas in the central part has a lower temperature and flows out from the cold end outlet 12; the gas in the outer part has a higher temperature and flows out from the hot end outlet 4. By dynamically adjusting the inlet pressure of the vortex tube and the opening of the hot-end electronic expansion valve control module 3, the temperature and flow rate of the airflow at both the cold and hot ends can be precisely controlled. For example, when the inlet pressure is increased, the temperature of the airflow at the cold end will decrease, and the temperature of the airflow at the hot end will increase; adjusting the opening of the electronic expansion valve to change the gas flow rate at the hot end will also affect the temperature at both the cold and hot ends accordingly.

[0036] The electronic expansion valve control module 3 consists of a high-precision electronic expansion valve driven by a stepper motor. The stepper motor receives pulse signals from the intelligent control unit and converts the electrical pulse signals into angular or linear displacement, precisely driving the valve core to change the flow area of ​​the valve port. The intelligent control unit calculates the required valve opening command based on the intake pressure-temperature transmission model, controls the stepper motor to operate, and achieves precise regulation of the airflow and pressure at the hot end of the vortex tube, thereby controlling the temperature at the hot and cold ends.

[0037] The installation scheme of the distributed sensor group 10 can include high-frequency pressure sensors at the hot end outlet 4 and high pressure inlet 11, PT1000 temperature sensors at the hot end outlet 4 and cold end outlet 12, flow sensors at multiple locations inside the vortex tube 1, and a Hall displacement sensor integrated on the valve stem of the electronic expansion valve, which can monitor temperature, pressure and valve stem displacement parameters in real time.

[0038] The intelligent control unit 9 is configured to perform the following operations:

[0039] A. Based on the intake pressure-temperature transfer model: ΔT=8.5*ln(P / 21)+0.12*α 1.5 The electronic expansion valve opening command is generated, where P is the intake pressure, ΔT is the temperature change between the cold end outlet 12 and the hot end outlet 4, α is the opening degree of the electronic expansion valve, and ln represents the natural logarithm.

[0040] The above model is used to describe the quantitative relationship between the temperature change of the hot and cold ends of the vortex tube and the intake pressure and the opening of the electronic expansion valve. It can be understood that the temperature change consists of two parts: one is proportional to the logarithm of the intake pressure (8.5 times the natural logarithm), and the other is proportional to the 1.5th power of the valve opening, with 0.12 as the multiplier.

[0041] In 8.5*ln(P / 21), 21 Bar is the constant pressure air source provided by the compressor, P / 21 represents the ratio of the current pressure to the reference pressure, and the logarithmic relationship indicates that the temperature effect of the vortex tube is logarithmically related to the intake pressure (based on the Joule-Thomson effect and the thermodynamic principle of the vortex tube). The higher the pressure, the lower the cold end temperature and the higher the hot end temperature, but the growth trend gradually slows down as the pressure increases (this is the characteristic of the logarithmic function); 8.5 is a coefficient, which is an empirical parameter obtained through experimental or simulation fitting, reflecting the intensity of the influence of pressure change on temperature. For example, when the pressure increases from 21 Bar to 42 Bar, ln(42 / 21)=ln2≈0.693, then the pressure term contributes 8.5*0.693≈5.89℃ of temperature change.

[0042] 0.12*α 1.5 The opening degree α of the electronic expansion valve (0-100%) directly affects the hot-end exhaust volume. A larger opening degree results in more high-temperature gas being discharged from the hot end and less low-temperature gas remaining at the cold end. This is key to decoupled temperature control between the hot and cold ends. The significance of 1.5 is that the effect of the opening degree on temperature is non-linear (similar to the square root relationship between flow rate and opening degree in fluid mechanics, but optimized to 1.5 based on the flow field characteristics of vortex tubes). The larger the opening degree, the more significant the effect of a unit change in opening degree on temperature. For example, when α = 0.5, α... 1.5 ≈0.35; when α=1, α 1.5=1, doubling the impact. The coefficient 0.12 characterizes the sensitivity of the opening to temperature changes. The smaller the value, the more significant the adjustment of the opening is required to noticeably change the temperature, in order to avoid over-adjustment.

[0043] The system uses sensors to collect the intake pressure P and the current valve opening α in real time. Substituting these values ​​into the model, the system can calculate the current temperature change ΔT, and then infer the actual temperature at the hot and cold ends (such as the target temperature T at the cold end). c =T0-ΔT, where T0 is the initial temperature).

[0044] For example, if the current pressure P = 21 Bar (reference pressure) and the opening α = 0 (valve fully closed), then ΔT = 8.5 * ln(1) + 0 = 0℃, that is, the temperature does not change; if P = 30 Bar and α = 0.5, then ΔT ≈ 8.5 * ln(30 / 21) + 0.12 * (0.5) 1.5 = 3.26℃ (assuming the cold end temperature drops by 3.26℃).

[0045] When it is necessary to control the cold end temperature, the intelligent control unit calculates the required valve opening α based on the deviation between the target temperature and the actual temperature, and drives the stepper motor to make precise adjustments.

[0046] For example, if the cold end temperature is too high, the opening α needs to be increased to allow more high-temperature gas to be discharged from the hot end and reduce the cold end temperature. The model can quantitatively calculate "how much to open" to achieve the goal.

[0047] B. By coordinating the compressor unit 8 and the electronic expansion valve control module 3 through a multivariable decoupling algorithm, dynamic operating condition disturbances are suppressed. Firstly, the multivariable decoupling algorithm decouples the two key control variables: compressor output pressure (affecting intake air volume) and electronic expansion valve opening (affecting hot-end exhaust volume). These variables jointly influence the hot and cold end temperatures of the vortex tube. For example, when the compressor pressure increases, the cold end temperature decreases, but this may simultaneously cause fluctuations in the hot end temperature; when the electronic expansion valve opening increases, the hot-end exhaust volume increases, the remaining cold-end air volume decreases, and the temperature rises. This coupling relationship makes it difficult for traditional control methods to simultaneously and accurately control both the hot and cold end temperatures. Therefore, the algorithm transforms the multivariable system into multiple independent single-variable systems, allowing the compressor to primarily control the cold end temperature (through pressure regulation), and the electronic expansion valve to primarily control the hot end temperature (through opening regulation). The two systems do not interfere with each other, achieving decoupled control of the hot and cold ends, with a temperature difference of up to 167℃.

[0048] Specifically, the multivariate decoupling algorithm includes the following:

[0049] a. Feedforward Compensation: This proactively anticipates and cancels out disturbances. Based on measurable disturbance signals such as compressor speed and vehicle acceleration, it predicts gas source pressure fluctuations in advance (e.g., during rapid vehicle acceleration, changes in compressor load cause instantaneous pressure fluctuations) and calculates the pre-adjusted opening of the electronic expansion valve, compensating before the disturbance affects the temperature. It collects compressor speed and vehicle acceleration signals in real time. When a sudden increase in speed is detected (e.g., during acceleration), it predicts a possible short-term increase in gas source pressure and pre-instructs the electronic expansion valve to slightly open, releasing some pressure and preventing a sudden drop in cold-end temperature. This can eliminate approximately 90% of predictable disturbances (e.g., compressor start-stop, vehicle acceleration / deceleration), with a response time of <0.2 seconds, more than 5 times faster than traditional feedback control.

[0050] b. Lyapunov Stability Optimization: Dynamically adjusting the PID controller to suppress overshoot. Traditional PID control is prone to overshoot under dynamic conditions (e.g., the target cold-end temperature is 20℃, but the actual temperature drops to 19℃ before rising again). Lyapunov stability theory can assess system stability in real time and automatically adjust PID parameters (proportional, integral, and derivative coefficients) to ensure a smooth, oscillating temperature regulation process. First, a Lyapunov function (an existing mathematical tool) is constructed to quantify the current instability of the system. Then, when the cold-end temperature overshoot approaches 0.5℃, the proportional coefficient of the PID controller is automatically reduced to decrease the regulation intensity. When the temperature approaches the target value, the integral coefficient is increased to eliminate static deviation, ultimately achieving an overshoot of <0.5℃. Compared to fixed PID parameters, the dynamically optimized control accuracy is improved by 3 times, making it particularly suitable for overshoot-sensitive scenarios such as power batteries.

[0051] C. Achieve temperature control accuracy of ±0.2℃ for cold end outlet 12 and ±1℃ for hot end outlet 4, and recover waste heat from the hot end for cabin heating. The cold end airflow (-40℃~+10℃) is used for ultra-low temperature cooling of the power battery and heat dissipation of electronic equipment; the hot end airflow (+50℃~+127℃) is used for cabin heating and motor preheating, increasing winter range by 18%.

[0052] In this embodiment, a two-stage pressure stabilization module is also included, located between the high-pressure inlet 11 and the compressor unit 8. This module includes a buffer tank 7 and a sonic nozzle 6 connected to the buffer tank 7. The buffer tank 7 contains a variable throttling component, which solves the problem of the fixed orifice plate in traditional buffer tanks being unable to dynamically compensate for flow resistance. Furthermore, in conjunction with the sonic nozzle, it suppresses gas source pressure fluctuations to ±0.35%, providing a stable input for the multi-stage vortex tube array. Specifically, the gas output from the compressor first enters the buffer tank 7. Due to its large volume, the buffer tank 7 acts as a buffer for the gas. When gas source pressure fluctuates, the buffer tank 7 can store or release some gas, reducing the pressure fluctuation amplitude. The variable throttling component can adjust the orifice size according to real-time changes in pipeline flow resistance, maintaining gas flow stability. For example, when pipeline flow resistance increases, the stepper motor controls the orifice plate diameter to increase, ensuring stable gas flow; conversely, the orifice diameter decreases.

[0053] The variable throttling assembly includes a fixed orifice plate with a flow hole and a movable orifice plate for controlling the flow area of ​​the flow hole. The movable orifice plate is driven by the actuator to slide along a direction perpendicular to the airflow. Through the cooperation of the movable orifice plate and the actuator, the variable throttling assembly can achieve precise and fast response control. It can work in conjunction with the stepper motor control algorithm of the electronic expansion valve (both adopt position closed-loop control) and synchronize data through the CAN bus to ensure that the adjustment phase difference between the buffer tank and EXV is <10ms.

[0054] The high precision design of the throat diameter of the sonic nozzle 6 is crucial for achieving high-precision flow control. Gas, initially pressurized by the buffer tank, enters the sonic nozzle, where, under a specific throat structure, the gas velocity reaches the speed of sound. According to gas dynamics principles, in this state, the gas flow rate is only related to the pressure and temperature at the nozzle inlet, as well as the nozzle throat size; external disturbances have minimal impact on the flow rate. Through a precisely designed throat diameter and stable inlet conditions, accurate control of the gas flow rate is achieved. The sonic nozzle 6 further stabilizes the gas flow rate, ensuring a flow deviation of ≤±1%. In conjunction with the buffer tank, it provides a stable gas source for the multi-stage vortex tube array, ensuring that the vortex tube 1 can stably generate airflows at different temperatures, meeting the system's temperature control requirements.

[0055] In this embodiment, the hot end outlet 4 is axially connected to a valve connecting seat 2, and the electronic expansion valve control module 3 is connected to the valve connecting seat 2. An air outlet 13 is opened on the side wall of the valve connecting seat 2. The valve core 5 of the electronic expansion valve control module 3 is installed in the valve connecting seat 2, which facilitates the installation of the electronic expansion valve control module 3 at the axial end of the vortex tube 1, avoids airflow deflection, does not require modification of the existing vortex tube 1, and has a low cost. The valve core 5 can be 17-4PH stainless steel plated with a diamond-like carbon film (thickness 3μm). The valve seat of the electronic expansion valve control module is made of precipitation hardening stainless steel (SUS630) and is ion nitrided (surface hardness ≥1000HV, nitriding layer depth 50μm±5μm).

[0056] As a specific control method in this embodiment, the present invention also provides a control method for an automotive intelligent temperature control system based on a vortex tube and an electronic expansion valve according to the first aspect, comprising the following steps:

[0057] S1. Initialize the system and set the target cold end temperature T at cold end outlet 12. c_target and the hot end waste heat recovery threshold T at the hot end outlet (4) hmin ;

[0058] Initialization is equivalent to defining the target during system startup, such as the cold junction target temperature T. c_target Based on current requirements (such as power battery cooling requiring -40℃, electronic equipment heat dissipation requiring 25℃), the required temperature value of the cold end is set manually or automatically. Its function is to set a "target anchor point" for subsequent control.

[0059] Hot-end waste heat recovery threshold T hmin =50℃: The preset lower limit of the hot end temperature. Only when the hot end temperature exceeds 50℃ is it considered that "the waste heat is sufficient to be recovered" (for example, heat above 50℃ is suitable for heating the car interior or preheating the motor, while heat below 50℃ is insufficient and recovery will not be started to avoid affecting the cold end temperature control). The waste heat recovery threshold avoids "ineffective recovery" (such as when the hot end temperature is 40℃, there is too little heat, and the recovered heat cannot provide effective heating and may also interfere with the cold end temperature control).

[0060] S2, Real-time acquisition of gas source pressure P via distributed sensor group 10 in Traffic Q in Cold junction temperature T c and hot end temperature T h P in The compressor output air pressure (unit: Bar, reference value 21 Bar) reflects whether the air supply is stable. ； Q in To ensure proper intake airflow and normal operation of the two-stage voltage regulator module (flow deviation ≤ ±1%); T c and Th Real-time temperature at both hot and cold ends is used to determine whether the target has been reached or if adjustments are needed. High-frequency acquisition (such as a pressure sensor with a sampling rate of 1kHz) ensures that data is not delayed under dynamic operating conditions, such as timely capture of pressure fluctuations when the vehicle accelerates rapidly.

[0061] S3. According to the model, ΔT = 8.5 * ln(P / 21) + 0.12 * α 1.5 Calculate the current valve opening α current This step utilizes the "temperature-pressure-opening" mathematical model from the patent to deduce the required opening degree of the electronic expansion valve, given the current gas source pressure P (P collected from S2). in The effect of pressure on temperature is calculated as 8.5ln(P / 21); combined with the target cold junction temperature T. c_target With actual temperature T c The deviation is calculated to determine the required temperature change ΔT = T. c_target -T c The opening α of the electronic expansion valve can be obtained by inverse modeling. current This refers to "how much should the valve be opened to achieve the target temperature"; this step uses a mathematical model to replace "experience-based adjustment", making the valve opening calculation more accurate and avoiding the traditional manual adjustment of screws by feel.

[0062] S4, if T c -T c_target If the temperature is greater than 0.5℃, fuzzy PID control will be activated to correct α. current To α new , where α new The main function of this step, for the corrected opening degree, is deviation judgment: if the deviation between the actual cold end temperature and the target temperature exceeds 0.5℃ (e.g., target 20℃, actual 20.6℃ or 19.4℃), it indicates that the calculation based solely on the S3 model is insufficient, and secondary adjustment is required. The meaning of PID control is: traditional methods adjust using three parameters—proportional (P), integral (I), and derivative (D)—and calculate the correction amount based on the current deviation, historical deviation accumulation, and deviation change rate. The meaning of fuzzy PID control is: considering the nonlinear characteristics of the vortex tube (the influence of pressure and opening degree on temperature is not a simple linear relationship), dynamically adjust the PID parameters using "fuzzy logic" (e.g., increase the adjustment force when the deviation is large, and decrease the force when approaching the target), avoiding overshoot or lag, and finally obtaining the corrected opening degree α. new This drives the electronic expansion valve to operate;

[0063] When T h >T hmin When the waste heat recovery is activated, press Q. heat =K·(T) h -T hmin Distribute hot-end flow, Q heatThe hot-end flow rate allocated to waste heat recovery, K is a proportional coefficient preset according to the system design, used to control the intensity of waste heat utilization. The main meaning of this step is the waste heat recovery trigger condition: when the hot-end temperature exceeds 50℃, the waste heat utilization mode is activated, introducing high-temperature airflow (50℃~127℃) into the cabin heating or motor preheating, replacing the traditional power-consuming PTC heating. T h -T hmin The temperature difference between the actual temperature at the hot end and the threshold temperature. The larger the temperature difference, the more flow rate is allocated. For example, T h =At 80℃, the distribution flow ratio T h =60℃ (more). In this technical solution, the waste heat from the hot end, which would otherwise be directly discharged and wasted, is reduced, thus reducing battery energy consumption (the system energy efficiency ratio COP reaches 0.48, saving 42% more energy than traditional PTC). Moreover, it can achieve intelligent allocation: allocating flow on demand, avoiding excessive recovery that would cause a sudden drop in hot end temperature (affecting cold end temperature control), or insufficient recovery that would lead to heat waste. For example, when the cabin requires a lot of heat in winter, if T h =100℃, then allocate more flow; if T h =55℃, then less allocation, prioritizing the accuracy of cold end temperature control.

[0064] It should be noted that all directional indicators (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicator will also change accordingly.

[0065] Furthermore, in this invention, descriptions involving "first," "second," etc., are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly and specifically defined.

[0066] In this invention, unless otherwise explicitly specified and limited, the terms "connection," "fixed," etc., should be interpreted broadly. For example, "fixed" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection or an electrical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0067] Furthermore, the technical solutions of the various embodiments of the present invention can be combined with each other, but only if they are feasible for those skilled in the art. If the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by the present invention.

Claims

1. An intelligent automotive temperature control system based on vortex tubes and electronic expansion valves, including: The vortex tube (1) has a cold end outlet (12), a hot end outlet (4) and a high pressure inlet (11); The compressor unit (8), connected to the high-pressure inlet (11) and supplying high-pressure gas into the vortex tube (1), is characterized by further comprising: The electronic expansion valve control module (3) is connected to the hot end outlet (4) of the vortex tube (1) along the axial direction of the vortex tube (1) and adjusts the flow rate of the hot end outlet (4) through the valve port of the electronic expansion valve. A distributed sensor group (10) includes at least a pressure sensor, a temperature sensor and a flow sensor, distributed at the cold end outlet (12) and / or the hot end outlet (4) and / or the high pressure inlet (11); The intelligent control unit (9) is electrically connected to the compressor unit (8), the electronic expansion valve control module (3), and the distributed sensor group (10). The intelligent control unit (9) is configured to perform the following operations: A. Based on the intake pressure-temperature transfer model: ΔT=8.5*ln(P / 21)+0.12*α 1.5 , generates an electronic expansion valve opening command, where P is the intake pressure, ΔT is the temperature change between the cold end outlet (12) and the hot end outlet (4), and α is the opening degree of the electronic expansion valve; B. By using a multivariable decoupling algorithm to coordinate the compressor unit (8) and the electronic expansion valve control module (3), dynamic operating condition disturbances are suppressed. C. Achieve a temperature control accuracy of ±0.2℃ for the cold end outlet (12) and ±1℃ for the hot end outlet (4), and recover waste heat from the hot end for cabin heating.

2. The automotive intelligent temperature control system based on vortex tube and electronic expansion valve according to claim 1, characterized in that: It also includes a two-stage pressure regulating module, which is set between the high-pressure inlet (11) and the compressor unit (8), including a buffer tank (7) and a sonic nozzle (6) connected to the buffer tank (7), wherein the buffer tank (7) is provided with a variable throttling component.

3. The automotive intelligent temperature control system based on vortex tube and electronic expansion valve according to claim 2, characterized in that: The variable throttling assembly includes a fixed orifice plate with flow holes and a movable orifice plate for controlling the flow area of ​​the flow holes. The movable orifice plate is driven by an actuator to slide in a direction perpendicular to the airflow.

4. The automotive intelligent temperature control system based on vortex tube and electronic expansion valve according to claim 1, characterized in that: The multivariable decoupling algorithm includes: a. Based on the compressor speed and vehicle acceleration, predict pressure fluctuations and adjust the opening of the electronic expansion valve in advance; b. Use the Lyapunov function to evaluate the system stability and automatically adjust the PID parameters to ensure that the overshoot of the cold end outlet (12) is <0.5℃.

5. The automotive intelligent temperature control system based on vortex tube and electronic expansion valve according to claim 1, characterized in that: The electronic expansion valve control module (3) consists of a high-precision electronic expansion valve driven by a stepper motor.

6. The automotive intelligent temperature control system based on eddy current tube and electronic expansion valve according to claim 1, characterized in that: The hot end outlet (4) is axially connected to a valve connecting seat (2), the electronic expansion valve control module (3) is connected to the valve connecting seat (2), the valve connecting seat (2) has an air outlet (13) on its side wall, and the valve core (5) of the electronic expansion valve control module (3) is installed in the valve connecting seat (2).

7. A control method for an automotive intelligent temperature control system based on a vortex tube and an electronic expansion valve according to any one of claims 1-6, characterized in that, Includes the following steps: S1. Initialize the system and set the target cold end temperature T at the cold end outlet (12). c_target and the hot end waste heat recovery threshold T at the hot end outlet (4) hmin ; S2. Real-time acquisition of gas source pressure P through distributed sensor group (10) in Traffic Q in Cold junction temperature T c and hot end temperature T h； S3. According to the model, ΔT = 8.5 * ln(P / 21) + 0.12 * α 1.5 Calculate the current valve opening α current ; S4, if T c -T c_target If the temperature is greater than 0.5℃, fuzzy PID control will be activated to correct α. current To α new , where α new The corrected opening; When T h >T hmin When the waste heat recovery is activated, press Q. heat =K·(T) h -T hmin Distribute hot-end flow, Q heat K is the proportional coefficient preset according to the system design, which is used to control the intensity of waste heat utilization and allocate the hot end flow rate to waste heat recovery.

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