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

Abstract

The invention discloses an automobile intelligent temperature control system and control method based on a vortex tube and an electronic expansion valve, and the system comprises the vortex tube which is provided with a cold end outlet, a hot end outlet and a high-pressure inlet; the compressor unit is communicated with the high-pressure inlet and sends high-pressure gas into the vortex tube, and the electronic expansion valve regulation and control module is connected with the hot end outlet of the vortex tube in the axial direction of the vortex tube and adjusts the flow of the hot end outlet through a valve port of an electronic expansion valve; the distributed sensor group at least comprises a pressure sensor, a temperature sensor and a flow sensor which are distributed at the cold end outlet and / or the hot end outlet and / or the high-pressure inlet; and the intelligent control unit is electrically connected with the compressor unit, the electronic expansion valve regulation and control module and the distributed sensor group. The electronic expansion valve and the multi-stage vortex tube array are deeply integrated, and the problems that in the prior art, a mechanical screw adjusting scheme is low in adjusting precision, delayed in response and short in service life can be solved.

Description

Technical Field

[0001] The present invention relates to the technical field of new energy vehicle thermal management technology, and specifically to an intelligent temperature control system and control method for vehicles based on a vortex tube and an electronic expansion valve. Background Technique

[0002] The multi-stage vortex tube array plays a key role in the vehicle temperature control system. After the compressed gas enters the vortex tube from the air inlet, under the guidance of the double helix reverse flow channel, a high-speed spiral motion is formed. 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; the gas in the outer layer has a higher temperature and flows out from the hot end outlet.

[0003] The traditional adjustment of the hot end temperature of the vortex tube relies on a mechanical adjustment screw, which has the following defects:

[0004] 1. Low adjustment accuracy: The screw pitch is usually 0.5 - 1 mm, and a single turn of rotation can only achieve a sub-millimeter-level displacement, while the adjustment of the hot end flow rate of the vortex tube requires a micron-level opening change (such as the valve port flow area is 0.05 - 2.5 mm 2 ). Manual operation is limited by the control accuracy of finger force (the minimum distinguishable displacement > 50 μm), and the actual opening control error > 10%, resulting in a cold end temperature fluctuation of ±2 °C (for example, when the target is 25 °C, it actually oscillates between 23 - 27 °C). The cooling of the power battery of a new energy vehicle requires ultra-low temperature precise control of -40 °C ± 0.2 °C. The temperature drift of the traditional scheme will cause the accelerated attenuation of battery active materials (the service life is shortened by more than 30%); the heat dissipation of electronic devices requires 25 °C ± 0.5 °C, and exceeding the temperature standard will cause faults such as CPU frequency reduction and chip solder joint failure;

[0005] 2. Response hysteresis: The vortex tube temperature control system needs to respond in real time to dynamic working conditions such as the start and stop of the compressor, vehicle acceleration and deceleration, and sudden changes in ambient temperature (the temperature change rate > 3 °C / s), but the mechanical adjustment has three types of hysteresis: First is the operation delay. After manually perceiving the temperature deviation, it is necessary to stop the vehicle, locate the screw, and perform the screwing operation. The total response time > 5 seconds, which is much higher than the working condition change period (for example, the air flow parameter change period during rapid acceleration < 1 second); then is the mechanical inertia. There is a backlash gap (> 50 μm) between the screw and the valve seat thread pair, and the adjustment process needs to overcome the friction force (the static friction coefficient > 0.3), resulting in an opening adjustment rate < 0.1 mm / s, which cannot suppress the temperature overshoot in time. Taking the sudden heat dissipation demand of electronic devices during high-speed driving as an example, the traditional scheme causes the device temperature to first rise rapidly to 80 °C (exceeding the safety threshold of 70 °C) due to response lag, and then slowly drop. Long-term such situations will cause thermal fatigue cracking of the circuit board solder joints;

[0006] 3. Short lifespan: The on-vehicle environment has high-frequency vibrations (5 - 200 Hz, acceleration > 5g) and alternating temperatures (-40°C - 85°C), which lead to fatal failures in mechanical adjustment structures. The thread pair (usually made of stainless steel / copper alloy) undergoes micro-displacements during vibrations, and adhesive wear and abrasive wear occur on the contact surface. After 5000 cumulative adjustments, the pitch error > 5%, resulting in out-of-control opening (e.g., the target opening is 20% but actually reaches 25%). The maintenance cycle of the traditional solution is < 6 months. It is necessary to disassemble the vortex tube assembly to replace the screw. The single maintenance time at the after-sales service points of new energy vehicles is > 2 hours, and the cost is > 500 yuan. The risk of thread pair fracture (especially under the vibration condition of 21Bar high-pressure air source) may cause leakage of hot-end air flow, and high-temperature gas (127°C) is sprayed into the cockpit or circuit board, posing risks of burns and short circuits.

[0007] Although existing technologies (such as patent CN113587123A) have tried to use solenoid valves for adjustment, they have not been optimized for the hot-end flow field characteristics of the vortex tube, resulting in large air flow disturbances and poor control linearity (error > ±1.5°C). Summary of the Invention

[0008] The present invention provides an intelligent vehicle temperature control system and control method based on a vortex tube and an electronic expansion valve. By deeply integrating the electronic expansion valve with a multi-stage vortex tube array, it can solve the problems of low adjustment accuracy, response hysteresis, and short lifespan in the mechanical screw adjustment scheme of the existing technology.

[0009] To achieve the above object, in the first aspect, the present invention provides the following technical solution: An intelligent vehicle temperature control system based on a vortex tube and an electronic expansion valve, including: a vortex tube, which has a cold-end outlet, a hot-end outlet, and a high-pressure inlet; a compressor unit, connected to the high-pressure inlet and sending high-pressure gas into the vortex tube. It also includes: an electronic expansion valve control module, connected to the hot-end outlet of the vortex tube along the axial direction of the vortex tube, and adjusting the flow rate of the hot-end outlet through the valve port of the electronic expansion valve; a distributed sensor group, at least including 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; an intelligent control unit, electrically connected to the compressor unit, the electronic expansion valve control module, and the distributed sensor group. 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 , generate an opening command for the electronic expansion valve, where P is the intake pressure, ΔT is the temperature change amount between the cold-end outlet and the hot-end outlet, and α is the opening degree of the electronic expansion valve;

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

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

[0013] The above technical solution coordinates the compressor and the electronic expansion valve through a multivariable decoupling algorithm to suppress the gas source pulsation. The temperature difference between the cold and hot ends is decoupled and regulated to reach 167 °C. Based on the intake pressure-temperature transfer model, precise control of ±0.2 °C at the cold end and ±1 °C at the hot end can be achieved; the waste heat at the hot end is recovered for cabin heating, and the system energy efficiency ratio reaches 0.48, saving 42% energy compared with the traditional PTC solution. The system simultaneously supports ultra-low temperature cooling of power batteries, constant temperature heat dissipation of electronic devices, and cabin comfort adjustment, and still maintains stable operation 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 fields.

[0014] As a supplement, it also includes a two-stage voltage stabilization module, which is arranged between the high-pressure inlet and the compressor unit, including a buffer tank and a sonic nozzle connected to the buffer tank. A variable throttling component is arranged inside the buffer tank, which solves the problem that the fixed orifice plate in the traditional buffer tank cannot dynamically compensate for the flow resistance. It also cooperates with the sonic nozzle to suppress the gas source pressure fluctuation within ±0.35%, providing a stable input for the multi-stage vortex tube array.

[0015] Preferably, the variable throttling component 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 an actuator to slide along a direction perpendicular to the air flow. Through the cooperation of the movable orifice plate and the actuator, precise and rapid response control of the variable throttling component can be achieved, which can cooperate with the stepping motor control algorithm of the electronic expansion valve (both use position closed-loop control), synchronize data through the CAN bus, and ensure that the adjustment phase difference between the buffer tank and the EXV < 10 ms.

[0016] Preferably, the multivariable decoupling algorithm includes:

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

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

[0019] Preferably, the electronic expansion valve control module is composed of a high-precision electronic expansion valve driven by a stepper motor. The stepper motor receives the pulse signal sent by the intelligent control unit, converts the electrical pulse signal into an angular displacement or a linear displacement, accurately drives the valve core to act, and changes the flow area of the valve port. The intelligent control unit calculates the required valve opening command based on the intake pressure-temperature transfer model, controls the operation of the stepper motor, realizes the accurate regulation of the hot-end air flow rate and pressure of the vortex tube, and further regulates the cold and hot-end temperatures.

[0020] Preferably, a valve connection seat is axially connected to the hot-end outlet. The electronic expansion valve control module is connected to the valve connection seat. An air outlet is opened on the side wall of the valve connection seat. The valve core of the electronic expansion valve control module is installed in the valve connection seat, which is convenient for installing the electronic expansion valve control module at the axial end of the vortex tube, avoiding air flow deflection, without modifying the existing vortex tube, and having a lower cost.

[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, including the following steps:

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

[0023] S2. Real-time collect the gas source pressure P in , flow rate Q in , cold-end temperature T c and hot-end temperature T h；

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

[0025] S4. If T c - T c_target > 0.5 °C, start fuzzy PID regulation and correct α current to α new , where α new is the corrected opening;

[0026] When T h > T hmin , turn on waste heat recovery and allocate the hot-end flow rate according to Q heat = K·(T h - T hmin ), Q heatis the hot - end flow rate allocated for waste - heat recovery, and K is a proportionality coefficient preset according to the system design, which is used to control the intensity of waste - heat utilization.

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

[0028] By using the multivariable decoupling algorithm to coordinate the compressor and the electronic expansion valve, the air - source pulsation is suppressed, and the decoupling control of the temperature difference between the cold end and the hot end reaches 167 °C. Based on the intake - pressure - temperature transfer model, precise control of ±0.2 °C at the cold end and ±1 °C at the hot end can be achieved; the waste heat recovery at the hot end is used for cabin heating, and the system energy efficiency ratio reaches 0.48, saving 42% energy compared with the traditional PTC scheme. The system simultaneously supports the ultra - low - temperature cooling of power batteries, the constant - temperature heat dissipation of electronic devices, and the comfort adjustment of the cabin, and still maintains stable operation under dynamic conditions such as compressor start - stop and vehicle vibration, providing a highly reliable and energy - efficient solution for new - energy vehicles and the field of industrial precision temperature control. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is the overall sectional structure diagram of the present invention;

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

[0031] Reference Signs:

[0032] 1, vortex tube; 11, high - pressure inlet; 12, cold - end outlet; 13, air outlet; 2, valve connection seat; 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 DESCRIPTION OF THE EMBODIMENTS

[0033] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention.

[0034] Such as Figure 1-2As shown in the figure, the present invention provides the following technical solutions to solve the problems of low adjustment accuracy, response hysteresis, and short service life in the mechanical screw adjustment solution in the prior art: An intelligent automotive temperature control system based on a vortex tube and an electronic expansion valve, including: a vortex tube 1, the 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 sending high-pressure gas into the vortex tube 1, further including: an electronic expansion valve control module 3, axially connected to the hot end outlet 4 of the vortex tube 1 along the axis of the vortex tube 1, and adjusting the flow rate of the hot end outlet 4 through the valve port of the electronic expansion valve; a distributed sensor group 10, at least including 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; 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, the vortex tubes 1 can be installed and used in a parallel connection manner. Multiple vortex tubes 1 share a compressor unit 8. The material of the vortex tube body is austenitic stainless steel (06Cr19Ni10), formed by laser welding, with a wall thickness of 1.5 mm ± 0.1 mm, ensuring the structural strength and sealing performance. The internal flow channel is designed as a double spiral reverse flow channel, with a spiral 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 surface of the flow channel is treated by electrolytic polishing, with a roughness Ra ≤ 0.4 μm, which can reduce the gas flow resistance. After the compressed gas generated by the compressor unit 8 enters the vortex tube 1 from the high-pressure inlet 11, it forms a high-speed spiral motion under the guidance of the double spiral 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 layer has a higher temperature and flows out from the hot end outlet 4. By dynamically adjusting the intake pressure of the vortex tube and the opening degree of the hot end electronic expansion valve control module 3, the temperature and flow rate of the cold and hot end airflows can be precisely controlled. For example, when the intake pressure is increased, the temperature of the cold end airflow will decrease, and the temperature of the hot end airflow will increase; adjusting the opening degree of the electronic expansion valve to change the hot end gas flow rate will also correspondingly affect the temperatures of the cold and hot ends.

[0036] The electronic expansion valve control module 3 is composed of a high-precision electronic expansion valve driven by a stepping motor. The stepping motor receives the pulse signal sent by the intelligent control unit, converts the electrical pulse signal into an angular displacement or a linear displacement, and precisely drives the valve core to move, changing the valve port flow area. The intelligent control unit calculates the required valve opening degree command based on the intake pressure-temperature transfer model, controls the operation of the stepping motor, and realizes the precise adjustment of the hot end airflow flow rate and pressure of the vortex tube, thereby regulating the temperatures of the cold and hot ends.

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

[0038] The described 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 , generate an opening instruction for the electronic expansion valve, 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 changes at the hot and cold ends of the vortex tube and the intake pressure and the opening degree 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 degree. 0.12 is the coefficient.

[0041] 21 Bar in 8.5 * ln(P / 21) is the constant pressure gas source provided by the compressor. P / 21 represents the ratio of the current pressure to the reference pressure. The logarithmic relationship indicates that the temperature effect of the vortex tube is related to the logarithm of the intake pressure (based on the Joule-Thomson effect and the thermodynamics 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 experiments or simulation fitting, reflecting the influence intensity 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 a temperature change of approximately 8.5 * 0.693 ≈ 5.89 °C.

[0042] 0.12 * α 1.5 In the opening degree α of the electronic expansion valve (0 - 100%), it directly affects the hot end exhaust volume. The larger the opening degree, the more high-temperature gas is discharged from the hot end, and the less low-temperature gas remains at the cold end. This is the key to decoupling and regulating the temperatures at the hot and cold ends. The significance of the 1.5th power is that the influence 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 the 1.5th power in combination with the flow field characteristics of the vortex tube). The larger the opening degree, the more significant the influence of unit opening degree change on temperature. For example, when α = 0.5, α 1.5 ≈ 0.35; when α = 1, α 1.5= 1, the influence is doubled. The coefficient 0.12 characterizes the sensitivity of the opening degree to temperature changes. The smaller the value, the more significant the adjustment of the opening degree is required to significantly change the temperature. To avoid over-regulation.

[0043] The system collects the intake pressure P and the current valve opening degree α in real time through sensors. Substituting them into the model can calculate the current temperature change ΔT, and then inversely deduce the actual temperatures of the hot and cold ends (such as the target temperature T of 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 degree α = 0 (valve fully closed), then ΔT = 8.5 * ln(1) + 0 = 0 °C, 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 °C (assuming the cold end temperature drops by 3.26 °C).

[0045] When the cold end temperature needs to be controlled, the intelligent control unit calculates the required valve opening degree α through the model according to the deviation between the target temperature and the actual temperature, and drives the stepper motor for precise adjustment.

[0046] For example, if the cold end temperature is too high, the opening degree 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 target.

[0047] B. Coordinate the compressor unit 8 and the electronic expansion valve control module 3 through the multivariable decoupling algorithm to suppress dynamic operating condition disturbances. First, the multivariable decoupling algorithm decouples the two key control variables, the compressor output pressure (which affects the intake air volume) and the electronic expansion valve opening degree (which affects the hot end exhaust gas volume). They jointly affect the temperatures of the hot and cold ends of the vortex tube. For example, when the compressor pressure increases, the cold end temperature will drop, but at the same time, it may cause fluctuations in the hot end temperature; when the electronic expansion valve opening degree increases, the hot end exhaust gas volume increases, the remaining gas volume at the cold end decreases, and the temperature will rise. This coupling relationship makes it difficult for traditional control methods to precisely control the temperatures of the hot and cold ends simultaneously. Therefore, through the algorithm, the multivariable system is transformed into multiple independent single-variable systems, enabling the compressor to be mainly responsible for controlling the cold end temperature (through pressure adjustment), and the electronic expansion valve to be mainly responsible for controlling the hot end temperature (through opening degree adjustment). The two do not interfere with each other, achieving decoupled control of the hot and cold ends, and the temperature difference can reach 167 °C.

[0048] Specifically: The multivariable decoupling algorithm includes the following content:

[0049] a. Feedforward compensation: Anticipate in advance and actively offset disturbances. The principle is to predict the air source pressure fluctuations in advance based on measurable disturbance signals such as compressor speed and vehicle acceleration (for example, when the vehicle accelerates suddenly, the change in compressor load will cause instantaneous pressure fluctuations), and calculate the pre-adjusted opening of the electronic expansion valve to perform compensation before the disturbance affects the temperature. Continuously collect compressor speed and vehicle acceleration signals. When a sudden increase in speed is detected (such as in the acceleration condition), it is predicted that the air source pressure may increase temporarily, and the electronic expansion valve is commanded to open slightly in advance to release part of the pressure, avoiding a sudden drop in the cold-end temperature. In this way, about 90% of the predictable disturbances (such as compressor start / stop, vehicle acceleration / deceleration) can be eliminated, and the response time is <0.2 seconds, which is more than 5 times faster than traditional feedback control;

[0050] b. Lyapunov stability optimization: Dynamically adjust PID to suppress overshoot. Traditional PID control is prone to "overshoot" in dynamic conditions (for example, the cold-end temperature target is 20°C, but it actually drops to 19°C first and then rises). The Lyapunov stability theory can evaluate the system stability in real time and automatically adjust the PID parameters (proportional, integral, and differential coefficients) to ensure a smooth and oscillation-free temperature regulation process. First, construct a Lyapunov function (existing mathematical tools) to quantify the current "instability degree" of the system; then, when the overshoot of the cold-end temperature approaches 0.5°C, automatically reduce the proportional coefficient of PID to reduce the regulation intensity; when the temperature approaches the target value, increase the integral coefficient to eliminate the static deviation. Finally, the overshoot is <0.5°C. Compared with fixed PID parameters, the control accuracy after dynamic optimization is increased by 3 times, which is especially suitable for scenarios sensitive to overshoot such as power batteries.

[0051] C. Achieve a temperature control accuracy of ±0.2°C at the cold-end outlet 12 and ±1°C at the hot-end outlet 4, and recover the waste heat at the hot end for cabin heating. The cold-end air flow (-40°C to +10°C) is used for ultra-low temperature cooling of power batteries and heat dissipation of electronic devices; the hot-end air flow (+50°C to +127°C) is used for cabin heating and motor preheating, increasing the winter cruising range by 18%.

[0052] In this embodiment, it further includes a double-stage voltage stabilizing module, which is arranged between the high-pressure inlet 11 and the compressor unit 8 and includes a buffer tank 7 and a sonic nozzle 6 connected to the buffer tank 7. A variable throttling component is arranged inside the buffer tank 7, which solves the problem that the fixed orifice plate in the traditional buffer tank cannot dynamically compensate for the flow resistance. Moreover, in cooperation with the sonic nozzle, it suppresses the gas source pressure fluctuation within ±0.35%, providing a stable input for the multi-stage vortex tube array. Specifically, the gas output by the compressor first enters the buffer tank 7. Due to the large volume of the buffer tank 7, it can buffer the gas. When the gas source pressure fluctuates, the buffer tank 7 can store or release part of the gas to reduce the amplitude of the pressure fluctuation. The variable throttling component can adjust the orifice size according to the real-time change of the pipeline flow resistance to maintain the stability of gas flow. For example, when the pipeline flow resistance increases, the stepping motor controls the orifice plate diameter to increase to ensure stable gas flow; otherwise, it decreases the diameter.

[0053] Among them, the variable throttling component includes a fixed orifice plate with a flow-through hole and a movable orifice plate for controlling the flow-through area of the flow-through hole. The movable orifice plate is driven by an actuator to slide along the direction perpendicular to the gas flow. Through the cooperation of the movable orifice plate and the actuator, precise and rapid response control of the variable throttling component can be achieved, which can cooperate with the stepping motor control algorithm of the electronic expansion valve (both adopt position closed-loop control), synchronize data through the CAN bus, and ensure that the adjustment phase difference between the buffer tank and the EXV is <10 ms.

[0054] The design accuracy of the throat diameter of the sonic nozzle 6 is relatively high, which is the key to its realization of high-precision flow control. The gas preliminarily stabilized by the buffer tank enters the sonic nozzle. Under a specific throat structure, the gas velocity reaches the speed of sound. According to the principle of gas dynamics, in this state, the gas flow rate is only related to factors such as the pressure and temperature at the nozzle inlet and the throat size of the nozzle, and the external interference has little influence on the flow rate. Through the precisely designed throat diameter and stable inlet conditions, precise control of the gas flow rate is achieved. The sonic nozzle 6 can further stabilize the gas flow rate, making the flow rate deviation ≤ ±1%. In cooperation 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 gas flows at different temperatures and meet the temperature control requirements of the system.

[0055] In this embodiment, a valve connection seat 2 is axially connected to the hot end outlet 4, the electronic expansion valve control module 3 is connected to the valve connection seat 2, an air outlet 13 is formed in the side wall of the valve connection seat 2, and the valve core 5 of the electronic expansion valve control module 3 is installed in the valve connection seat 2, which facilitates the installation of the electronic expansion valve control module 3 at the axial end of the vortex tube 1, avoids air flow deflection, and does not require modification of the existing vortex tube 1, with relatively low cost. The valve core 5 can be 17-4PH stainless steel coated with 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 subjected to ion nitriding treatment (surface hardness ≥ 1000HV, nitriding layer depth 50μm ± 5μm).

[0056] As a specific control method of 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, including the following steps:

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

[0058] Initialization is equivalent to when the system starts. First, clarify the goals. The cold end target temperature T c_target : According to the current requirements (such as -40°C for power battery cooling and 25°C for electronic device heat dissipation), manually or automatically set the temperature value that the cold end needs to reach, and its function is to set a "target anchor point" for subsequent control.

[0059] The hot end waste heat recovery threshold T hmin = 50°C: Preset the lower limit of the hot end temperature. Only when the hot end temperature exceeds 50°C is it considered that "the waste heat is sufficient for recovery" (for example, the heat above 50°C is suitable for heating the vehicle interior or preheating the motor, and when it is lower than 50°C, the heat is insufficient and the recovery is not 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°C, the heat is too little and cannot effectively heat after recovery, and may also interfere with the cold end temperature control).

[0060] S2. Real-time collect the gas source pressure P in , flow rate Q in , cold end temperature T c and hot end temperature T h through the distributed sensor group 10. P in is the gas source pressure output by the compressor (unit: Bar, reference value 21Bar), reflecting whether the gas source is stable; Q in is the intake flow rate to ensure the normal operation of the double-stage voltage stabilizing module (flow rate deviation ≤ ±1%); T c and T hThe real-time temperatures at the hot and cold ends are used to determine whether the target is reached or adjustment is needed. High-frequency acquisition (such as a pressure sensor sampling rate of 1 kHz) is adopted to ensure that data is not delayed under dynamic conditions. For example, pressure fluctuations can be captured in a timely manner during rapid vehicle acceleration.

[0061] S3. Calculate the current valve opening α according to the model ΔT = 8.5 * ln(P / 21) + 0.12 * α 1.5 This step uses the "temperature - pressure - opening" mathematical model in the patent to inversely calculate how much the electronic expansion valve needs to be opened. Given the current gas source pressure P (from the P collected in S2 current ), calculate the influence term of pressure on temperature 8.5ln(P / 21); combined with the target temperature T at the cold end in and the actual temperature T c_target , calculate the required temperature change ΔT = T c - T c_target , and inversely solve the opening α of the electronic expansion valve through the model c , that is, "how much the valve should be opened to reach the target temperature"; this step uses a mathematical model to replace "empirical adjustment", making the calculation of the valve opening more accurate and avoiding the traditional manual adjustment of turning the screw by feeling; current

[0062] S4. If T c - T c_target > 0.5 °C, start fuzzy PID adjustment to correct α current to α new , where α new is the corrected opening. The main function of this step is deviation judgment: if the deviation between the actual temperature at the cold end and the target temperature exceeds 0.5 °C (for example, the target is 20 °C, the actual is 20.6 °C or 19.4 °C), it means that relying solely on the model calculation in S3 is not enough and secondary adjustment is needed. The meaning of PID adjustment control is: the traditional method adjusts through three parameters: proportional (P), integral (I), and derivative (D), and calculates the correction amount based on the current deviation, historical deviation accumulation, and deviation change rate. The meaning of fuzzy PID adjustment is: for the non-linear characteristics of the vortex tube (the influence of pressure and opening on temperature is not a simple linear relationship), use "fuzzy logic" to dynamically adjust the PID parameters (for example, increase the adjustment strength when the deviation is large and decrease the strength when approaching the target), avoid overshoot or lag, and finally obtain the corrected opening α new , and drive the electronic expansion valve to act;

[0063] When T h > T hmin , turn on waste heat recovery and distribute the hot end flow according to Q heat = K · (T h - T hmin ), Q heatLet \(Q\) be the hot - end flow rate allocated for waste - heat recovery, and \(K\) be the proportionality coefficient preset according to the system design, which is used to control the intensity of waste - heat utilization. The main meaning of this step is the trigger condition for waste - heat recovery: when the hot - end temperature exceeds \(50^{\circ}C\), the waste - heat utilization mode is started, and the high - temperature air flow (\(50^{\circ}C - 127^{\circ}C\)) is introduced into the cabin heating or motor pre - heating to replace the traditional power - consuming PTC heating, \(T\) h \(-T\) hmin : The temperature difference between the actual hot - end temperature and the threshold value. The larger the temperature difference, the more the allocated flow rate. For example, when \(T\) h \( = 80^{\circ}C\), the allocated flow rate is more than when \(T\) h \( = 60^{\circ}C\)). In this technical solution, the waste heat at the hot end was originally directly discharged and wasted. It reduces the battery energy consumption (the system energy efficiency ratio COP reaches 0.48, saving 42% compared with the traditional PTC), and can achieve intelligent distribution: the flow rate is distributed according to demand, avoiding the sudden drop of the hot - end temperature caused by excessive recovery (affecting the cold - end temperature control), or insufficient recovery resulting in heat waste. For example, when a large amount of heat is required in the cabin in winter, if \(T\) h \( = 100^{\circ}C\), more flow rate is distributed; if \(T\) h \( = 55^{\circ}C\), less flow rate is distributed, giving priority to ensuring the cold - end temperature - control accuracy.

[0064] It should be noted that all directional indications (such as up, down, left, right, front, back...) in the embodiments of the present invention are only used to explain the relative positional relationship and movement conditions between components in a certain specific posture (as shown in the attached drawings). If this specific posture changes, the directional indication will also change accordingly.

[0065] In addition, in the present invention, descriptions such as "first" and "second" are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined as "first" and "second" may explicitly or implicitly include at least one of such features. In the description of the present invention, "a plurality" means at least two, such as two, three, etc., unless otherwise specifically and clearly defined.

[0066] In the present invention, unless otherwise clearly specified and limited, terms such as "connection" and "fixation" should be understood in a broad sense. For example, "fixation" can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and can be the internal communication of two components or the interaction relationship between two components, unless otherwise clearly limited. For those of ordinary skill in the art, the specific meanings of the above - mentioned terms in the present invention can be understood according to specific circumstances.

[0067] In addition, the technical solutions between various embodiments of the present invention can be combined with each other, but it must be based on the ability of those of ordinary skill in the art to implement. When the combination of technical solutions results in contradictions or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

Claims

1. An intelligent vehicle 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 sending high-pressure gas into the vortex tube (1), characterized by further comprising: An electronic expansion valve control module (3) connected to the hot end outlet (4) of the vortex tube (1) along the axial direction of the vortex tube (1), and adjusting the flow rate of the hot end outlet (4) through 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); 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), and 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 , generate an opening command for the electronic expansion valve, 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. Coordinating the compressor unit (8) and the electronic expansion valve control module (3) through a multivariable decoupling algorithm to suppress dynamic condition disturbances; C. Achieving a temperature control accuracy of ±0.2 °C at the cold end outlet (12) and a temperature control accuracy of ±1 °C at the hot end outlet (4), and recovering the waste heat at the hot end for cabin heating.

2. The automotive intelligent temperature control system based on a vortex tube and an electronic expansion valve according to claim 1, characterized in that: It further includes a two-stage voltage stabilizing module provided 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), and a variable throttling component is provided inside the buffer tank (7).

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

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

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

6. The automotive intelligent temperature control system based on a vortex tube and an electronic expansion valve according to claim 1, wherein: The hot end outlet (4) is axially connected to a valve connection seat (2), the electronic expansion valve control module (3) is connected to the valve connection seat (2), an air outlet (13) is opened on the side wall of the valve connection seat (2), and the valve core (5) of the electronic expansion valve control module (3) is installed inside the valve connection 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, Including the following steps: S1. Initialize the system and set the cold-end target temperature T of the cold-end outlet (12) c_target and the hot-end waste heat recovery threshold T of the hot-end outlet (4) hmin ; S2. Real-time collect the gas source pressure P through the distributed sensor group (10) in , the flow rate Q in , the cold-end temperature T c and the hot-end temperature T h； S3. Calculate the current valve opening α according to the model ΔT = 8.5 * ln(P / 21) + 0.12 * α 1.5 ; current ; S4. If T c -T c_target > 0.5 °C, then start fuzzy PID control to correct α current to α new , where α new is the corrected opening degree; When T h > T hmin When it is, the waste heat recovery is started, and the hot end flow rate is allocated according to Q heat = K·(T h - T hmin ), where Q heat is the hot end flow rate allocated to waste heat recovery, and K is a proportionality coefficient preset according to the system design, which is used to control the intensity of waste heat utilization.

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