Flexible microporous cold air cooling system and heat dissipation structure thereof

Abstract

The present application relates to cold air cooling technology field, disclose a kind of flexible micropore cold air cooling system and its heat dissipation structure, including cold source access end, flexible air duct body, low-frequency large flow electromagnetic air valve and sensing and control unit.Cold source access end introduces cold air, low-frequency large flow electromagnetic air valve is connected with the flexible air duct body of cold source access end.Sensing and control unit collects air temperature, relative humidity and target object surface temperature data, calculates dewing prevention safety boundary temperature, generates low-frequency pulse width modulation signal control air valve opening and closing.Cold air enters flexible air duct body when air valve is opened, and the self-excited oscillation pressure-sensitive micropore distributed on surface is subjected to high-frequency deformation under the action of alternating air pressure.The present application utilizes aerodynamic vortex to destroy the thermal boundary layer attached to the surface of target object to improve heat exchange efficiency, and dynamically adjusts cold input according to temperature change, maintains the dynamic balance of cooling and dewing prevention state, to avoid condensation.

Description

Technical Field

[0001] This invention relates to the field of cold air cooling technology, specifically a flexible microporous cold air cooling system and its heat dissipation structure. Background Technology

[0002] The flexible micro-pore cooling system is a temperature-controlled heat dissipation structure used for heat dissipation in local spaces or target objects. The system uses flexible tubular channels to transport the cooling medium and opens tiny holes in the tube wall to release the cooling air. The flexible material allows the air duct to adapt to complex installation environments and can be bent and arranged in narrow structural gaps to provide short-distance directional cooling air delivery to heat sources.

[0003] During operation, the low-temperature cold air generated by the external refrigeration equipment is sent into the flexible air duct. The cold air flows along the duct and, under the pressure inside the duct, is sprayed outward from the micropores distributed on the duct wall, directly blowing onto the surface of the heat-generating target object. The heat on the surface of the target object is carried away by the convection heat exchange with the cold air and dissipated into the surrounding air environment, thereby reducing the surface temperature of the target object.

[0004] Current air supply cooling technologies employ continuous air supply, which creates a stable thermal boundary layer of adhering fluid on the target surface, hindering heat transfer and limiting convective heat transfer efficiency. Increasing the air supply pressure to disrupt this thermal boundary layer increases system energy consumption and causes a rapid drop in the target surface temperature. When the surface temperature falls below the ambient critical dew point, condensation occurs, and the resulting water droplets can damage the heating equipment. Existing control methods often rely on setting fixed temperature thresholds to cut off the air supply, failing to dynamically adjust the anti-condensation boundary based on changes in ambient temperature and humidity. This results in an imbalance between anti-condensation and cooling requirements.

[0005] Therefore, the purpose of this invention is to provide a flexible microporous cold air cooling system and its heat dissipation structure to overcome the shortcomings of the prior art. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides a flexible microporous cold air cooling system and its heat dissipation structure, which solves the problems in existing flexible air supply cooling technologies, such as the formation of a thermal boundary layer during continuous air supply, which limits heat exchange efficiency, the difficulty in maintaining sufficient heat dissipation penetration under low energy consumption, and the inability of fixed temperature control methods to dynamically balance equipment cooling and anti-condensation risks.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] The first aspect of this invention provides a flexible microporous cold air cooling system, comprising: a cold source inlet, a flexible duct body, a low-frequency high-flow electromagnetic valve, and a sensing and control unit. Cold air is introduced through the cold source inlet; self-excited oscillating pressure-sensitive micropores are spaced apart on the surface of the flexible duct body; the low-frequency high-flow electromagnetic valve connects the cold source inlet and the flexible duct body; the sensing and control unit collects air temperature data, relative humidity data, and real-time temperature data of the target object's surface, calculates the anti-condensation safety boundary temperature, and compares the real-time temperature data with the anti-condensation safety boundary temperature to generate a low-frequency pulse width modulation signal, controlling the opening and closing of the low-frequency high-flow electromagnetic valve. When the low-frequency high-flow electromagnetic valve is open, cold air enters the flexible duct body. The self-excited oscillating pressure-sensitive micropores undergo high-frequency expansion and contraction deformation under the alternating air pressure generated by the fluid's self-excited oscillation, cutting the cold air into aerodynamic vortex rings and spraying them onto the target object's surface.

[0009] Furthermore, the flexible duct body is sequentially configured from the inside to the outside along its radial cross-section as follows: an airtight inner liner, a radial constraint layer, and an outer protective sleeve. The airtight inner liner defines the fluid transmission cavity, the radial constraint layer is composed of multiple non-stretchable fiber bundles interwoven, and the outer protective sleeve is made of porous foam material with interconnected micropores throughout. The flexible duct body of this system employs a radial constraint layer design. After the fiber bundles are interwoven, they form network nodes, generating tensile strength in the radial direction and limiting the radial expansion of the duct wall under fluid pressure. This radial constraint layer reduces the overall aerodynamic capacitance of the duct wall volume as air pressure rises. The fluid pressure wave output by the low-frequency, high-flow electromagnetic valve overcomes the pressure rise lag phenomenon during transmission in the flexible duct, maintaining the pressure rise directly transmitted along the gradient to the self-excited oscillating pressure-sensitive micropores, meeting the pressure threshold requirements for triggering fluid self-excited oscillation.

[0010] Furthermore, the interior of the self-excited oscillating pressure-sensitive microorifice is sequentially connected to a fluid inlet, an alternating deflection chamber, and an elastic deformation outlet along the airflow direction. Micro-recirculation cavities are symmetrically arranged on both sides of the alternating deflection chamber. After entering the alternating deflection chamber, cold air flows back along the micro-recirculation cavities, driving the main stream beam to deflect alternately, forming fluid self-excited oscillation. The elastic deformation outlet contracts at its end, forming a closed slit structure. This slit structure opens and closes at high frequency under the influence of alternating air pressure. The self-excited oscillating pressure-sensitive microorifice utilizes the wall-attachment effect of airflow. Cold air flows back in the micro-recirculation cavities, establishing a local high-pressure zone, driving the main stream beam to deflect at high frequency and generating alternating air pressure. Driven by high-frequency alternating air pressure, the slit structure periodically opens and closes, physically cutting off the continuously input cold flow. The squeezed-out cold air mass entrains surrounding still air, forming a discrete aerodynamic vortex ring with spin characteristics. This aerodynamic vortex ring impacts the surface of the target object, disrupting the fluid thermal boundary layer attached to the surface and improving convective heat transfer efficiency.

[0011] Furthermore, the specific method for calculating the anti-condensation safety boundary temperature is as follows: intermediate environmental variables are calculated based on collected air temperature and relative humidity data; the transient dew point temperature is estimated based on the intermediate environmental variables; and the anti-condensation safety margin variable is calculated by adding the transient dew point temperature to the anti-condensation safety margin variable set based on the thermal property parameters of the target object. The sensing and control unit incorporates nonlinear mapping calculation logic, which uses empirical formulas to obtain intermediate variables reflecting the vaporization characteristics of the environment based on current ambient temperature and humidity parameters, and derives the critical dew point temperature for water vapor saturation. By introducing anti-condensation safety margin variables that reflect the specific heat capacity, thermal conductivity, and thermal inertia characteristics of the target object, the anti-condensation safety boundary temperature is dynamically constructed, providing a benchmark for condensation risk assessment.

[0012] Furthermore, the specific method for generating a low-frequency pulse width modulation signal by comparing real-time temperature data with the anti-condensation safety boundary temperature is as follows: When the downward trend of the real-time temperature data indicates that the real-time temperature data is approaching the anti-condensation safety boundary temperature, the sensing and control unit reduces the duty cycle of the low-frequency pulse width modulation signal or outputs a cutoff level, controlling the low-frequency high-flow solenoid valve to close. When the real-time temperature data rises above the anti-condensation safety boundary temperature, the sensing and control unit increases the duty cycle of the low-frequency pulse width modulation signal, controlling the low-frequency high-flow solenoid valve to open. The system adjusts the cooling input according to the real-time temperature drop rate. During the valve closing cycle, the surface temperature rises due to the heat generated by the target object and its own heat capacity, thus breaking away from the thermodynamic condensation conditions of water molecules and maintaining a dynamic balance between cooling and anti-condensation states.

[0013] Furthermore, the sensing and control unit acquires the actual installation distance between the self-excited oscillating pressure-sensitive micro-orifice on the flexible duct body and the surface of the target object. The sensing and control unit compares the actual installation distance with a preset distance judgment threshold. When the actual installation distance is greater than the preset distance judgment threshold, the sensing and control unit determines that the flexible duct body is in a suspended working mode; when the actual installation distance is less than or equal to the preset distance judgment threshold, the sensing and control unit determines that the flexible duct body is in an embedded working mode. The sensing and control unit calculates the compensated opening time of the low-frequency high-flow solenoid valve based on the actual installation distance. When the flexible duct body is in a suspended working mode, the compensated opening time is greater than the basic opening time, and the sensing and control unit controls the low-frequency high-flow solenoid valve to extend the single conduction time; when the flexible duct body is in an embedded working mode, the compensated opening time is less than or equal to the basic opening time, and the sensing and control unit controls the low-frequency high-flow solenoid valve to shorten the single conduction time. The above control mechanism performs momentum dissipation compensation calculations based on the injection distance from the self-excited oscillating pressure-sensitive micro-orifice to the target object. In the suspension mode, the valve turn-on time is increased to enhance the peak back pressure inside the system, allowing the aerodynamic vortex ring to gain greater initial momentum to offset the kinetic energy decay during space flight. In the embedded mode, the valve turn-on time is shortened to limit the jet momentum and avoid causing localized quenching of the target object in a confined space.

[0014] A second aspect of the present invention provides a flexible microporous cooling and heat dissipation structure, applied to the flexible microporous cooling and heat dissipation system described in the first aspect, comprising:

[0015] A multi-layered composite tubular flexible air duct body, wherein the flexible air duct body is provided with an airtight inner liner layer, a radial constraint layer and an outer protective sleeve in sequence from the inside to the outside along the radial cross section. The airtight inner liner layer is molded from thermoplastic polyurethane elastomer material and defines a fluid transmission cavity inside. The radial constraint layer covers the outer peripheral surface of the airtight inner liner layer. The radial constraint layer is formed by multiple non-stretchable fiber bundles interlaced in a large braiding angle spiral winding manner to form network nodes. The outer protective sleeve is attached and fixed to the outside of the radial constraint layer. The outer protective sleeve is made of porous foam material with interconnected micropores inside.

[0016] Multiple self-excited oscillating pressure-sensitive micropores are embedded in the wall of the flexible air duct body. The interior of each self-excited oscillating pressure-sensitive micropore is sequentially connected along the airflow direction to a fluid inlet for receiving cold air from the fluid transmission chamber, an alternating deflection chamber, and an elastic deformation outlet. Micro-recirculation cavities are symmetrically arranged on both sides of the alternating deflection chamber. The elastic deformation outlet is made of elastic polymer material and contracts at the end to form a closed slit structure.

[0017] This invention provides a flexible microporous cold air cooling system and its heat dissipation structure. It has the following beneficial effects:

[0018] 1. This invention, by setting a flexible air duct body and self-excited oscillating pressure-sensitive micropores distributed at intervals on the surface, introduces cold air into the flexible air duct body when the low-frequency high-flow electromagnetic valve is opened. The self-excited oscillating pressure-sensitive micropores undergo high-frequency expansion and contraction deformation under the action of alternating air pressure generated by the self-excited oscillation of the fluid, cutting the continuously input cold air into aerodynamic vortex rings and spraying them onto the surface of the target object. The initial impulse carried by the aerodynamic vortex rings is used to destroy the thermal boundary layer attached to the surface of the target object, thereby improving the convective heat transfer efficiency.

[0019] 2. This invention utilizes a sensing and control unit to collect air temperature data, relative humidity data, and real-time temperature data of the target object's surface. It calculates the anti-condensation safety boundary temperature and compares the real-time temperature data with the anti-condensation safety boundary temperature to generate a low-frequency pulse width modulation signal to control the opening and closing of a low-frequency, high-flow electromagnetic valve. The system dynamically adjusts the amount of cold air input based on real-time temperature changes. During the valve closing cycle, the surface temperature rises due to the heat generated by the target object and its own heat capacity, thus breaking away from the thermodynamic condensation conditions of water molecules and maintaining a dynamic balance between cooling and anti-condensation states.

[0020] 3. This invention, in conjunction with a low-frequency, high-flow electromagnetic valve and a self-excited oscillating pressure-sensitive micro-orifice, achieves multi-stage pulsed air delivery. The low-frequency, high-flow electromagnetic valve is controlled by a low-frequency pulse width modulation signal to output a low-frequency cold airflow. The cold airflow is conducted within the flexible duct body to the self-excited oscillating pressure-sensitive micro-orifice, triggering high-frequency fluid segmentation. The macroscopic low-frequency cold air input and the microscopic high-frequency fluid segmentation work together to ensure that the aerodynamic vortex ring has sufficient jet impulse while reducing the energy consumption of continuous air supply, thereby enhancing the heat dissipation penetration capability of the cooling system in complex spaces. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the overall structure of the present invention.

[0022] Figure 2 This is a right view of the present invention;

[0023] Figure 3 This is a system architecture diagram of the present invention;

[0024] Figure 4 This is a flowchart illustrating the overall process of the method of the present invention.

[0025] Figure 5 This is a dynamic coordinated control curve of the outer casing temperature and duty cycle of the present invention;

[0026] Figure 6 A comparison diagram of convective heat transfer coefficients for different control strategies of the present invention;

[0027] Figure 7 This is a comparison curve showing the effect of the anti-interference frequency control of the present invention on chip temperature.

[0028] Among them, 100 is the flexible air duct body; 101 is the airtight inner liner layer; 102 is the radial constraint layer; 103 is the outer protective sleeve; 104 is the self-excited oscillation pressure-sensitive micropore; and 200 is the low-frequency high-flow electromagnetic valve. Detailed Implementation

[0029] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] Please see the appendix Figure 1 Appendix Figure 2 With appendix Figure 3 This invention provides a flexible microporous cold air cooling system and its heat dissipation structure, including: a cold source inlet, a low-frequency high-flow electromagnetic valve 200, a sensing and control unit, and a flexible air duct body 100.

[0031] The cold source inlet is connected to an external refrigeration device, which outputs cold air at a temperature lower than the ambient temperature. The cold source inlet introduces this cold air into the system. The input of the low-frequency, high-flow solenoid valve 200 is connected to the cold source inlet, and the output of the low-frequency, high-flow solenoid valve 200 is connected to the flexible duct body 100. The low-frequency, high-flow solenoid valve 200 is used to control the conduction and cut-off states of cold air entering the flexible duct body 100. The sensing and control unit is electrically connected to the low-frequency, high-flow solenoid valve 200. The sensing and control unit is used to output control signals to adjust the opening and closing actions of the low-frequency, high-flow solenoid valve 200. The surface of the flexible duct body 100 is spaced together with multiple self-excited oscillating pressure-sensitive micropores 104, which connect the inner cavity of the flexible duct body 100 to the external environment.

[0032] See attached document Figure 4 The control process includes:

[0033] The sensing and control unit collects real-time data on the air temperature and relative humidity of the target's operating environment, as well as the real-time temperature of the target object's surface.

[0034] The sensor and control unit calculates the transient dew point temperature based on the acquired air temperature and relative humidity data. The sensor and control unit then combines the transient dew point temperature with the preset thermophysical parameters of the target object to calculate the anti-condensation safety boundary temperature.

[0035] The sensing and control unit compares the real-time temperature data of the target object's surface with the anti-condensation safety boundary temperature. Based on the comparison result, the sensing and control unit generates a low-frequency pulse width modulation signal.

[0036] The sensing and control unit sends a low-frequency pulse width modulation signal to the low-frequency high-flow solenoid valve 200. The low-frequency high-flow solenoid valve 200 performs opening and closing actions according to the duty cycle of the low-frequency pulse width modulation signal.

[0037] During the period when the low-frequency high-flow electromagnetic valve 200 is in the open state, cold air enters the flexible air duct body 100, and the air pressure inside the flexible air duct body 100 is transmitted to the self-excited oscillating pressure-sensitive micropore 104.

[0038] After receiving air pressure, the self-excited oscillating pressure-sensitive micropore 104 guides the cold air to deflect through the micro-reflux cavity structure configured inside the self-excited oscillating pressure-sensitive micropore 104, triggering fluid self-excited oscillation. The fluid self-excited oscillation generates alternating air pressure, which acts on the pore wall of the self-excited oscillating pressure-sensitive micropore 104, causing the self-excited oscillating pressure-sensitive micropore 104 to undergo high-frequency expansion and contraction deformation.

[0039] The high-frequency deformation of the self-excited oscillating pressure-sensitive micro-orifice 104 divides the flowing cold air into aerodynamic vortex rings. The aerodynamic vortex rings are then ejected from the self-excited oscillating pressure-sensitive micro-orifice 104 onto the surface of the target object.

[0040] During the period when the low-frequency, high-flow electromagnetic valve 200 is in the closed state, cold air stops entering the flexible air duct body 100. The heat generated inside the target object is conducted to the surface of the target object, causing the surface temperature of the target object to rise. The surface temperature of the target object tends to rise above the anti-condensation safety boundary temperature.

[0041] The flexible duct body 100 is formed using a multi-layer composite tubular structure. Different functional layers are distributed from the inside to the outside along the radial cross-section of the flexible duct body 100. An airtight inner liner layer 101 is provided as the innermost basic structure of the flexible duct body 100. The airtight inner liner layer 101 defines a fluid transmission cavity inside. The airtight inner liner layer 101 is formed using thermoplastic polyurethane elastomer material. In order to maintain the airtightness of the pipeline when physical bending occurs, the specific extrusion process of the thermoplastic polyurethane elastomer pipe can be set by those skilled in the art with reference to existing pipe manufacturing specifications. The plastic extrusion molding method of thermoplastic polyurethane elastomer pipe is a well-known technology in the field and will not be described in detail here.

[0042] A radial constraint layer 102 is wrapped around the outer periphery of the airtight inner liner 101. The radial constraint layer 102 is composed of multiple non-stretchable fiber bundles woven together. The fiber bundles include aramid fibers or stainless steel microfilaments. Since ordinary weaving structures may restrict radial and axial deformation at the same time, in order to achieve anisotropic characteristics, the fiber bundles are woven together on the outside of the airtight inner liner 101 in a spiral winding manner with a large weaving angle. After the fiber bundles are woven together, they form network nodes. When the fluid pressure inside the airtight inner liner 101 is squeezed outward, the woven fiber bundles generate tensile force in the radial direction, which restricts the radial expansion of the pipe wall. At the same time, the grid gaps formed by the fiber bundles allow the airtight inner liner 101 to bend and deform along the pipe axis. This structural design achieves the isolation of the axial deformation capacity of the pipe wall and the radial rigid constraint in terms of physical equivalence.

[0043] An outer protective sleeve 103 is attached and fixed to the outside of the radial constraint layer 102. The outer protective sleeve 103 is made of porous foam material. The porous foam material is filled with interconnected micropores. When cold air flows at high frequency inside the flexible air duct body 100 and generates frictional sound waves, the sound waves enter the micropores and generate air viscous friction, converting sound energy into heat energy and dissipating it.

[0044] During the opening cycle of the low-frequency, high-flow electromagnetic valve 200, the cold air is controlled to enter the fluid transmission chamber in the form of a step pressure wave. If the pipe wall is easily expandable, the fluid pressure entering the fluid transmission chamber will first be consumed in the action of expanding the pipe wall, resulting in a weakening of the airflow pressure transmitted to the depth of the pipe and a time delay. However, after introducing the radial constraint layer 102, it is equivalent to adding a rigid blocking surface to the outside of the flexible pipe, so that the fluid energy is used more to drive the internal gas to be transmitted in a straight line along the axial direction. The radial deformation of the pipe wall of the flexible duct body 100 in response to the step pressure wave input to the fluid transmission chamber follows the following physical equation:

[0045] ;

[0046] In the formula, This represents the radial deformation increment of the outer wall of the airtight inner liner 101. This represents the pressure difference increment between the transient fluid pressure inside the fluid transmission chamber and the external ambient air pressure. This represents the initial inner radius of the fluid transport cavity. This indicates the effective compressive strength of the wall formed by the airtight inner liner 101 and the radial restraint layer 102. This represents the composite radial elastic modulus of the flexible air duct body 100 when including the radial constraint layer 102.

[0047] The non-stretchable fiber bundles in the radial constraint layer 102 significantly increase the value of the composite radial elastic modulus. In the equation, when the composite radial elastic modulus in the denominator increases, the corresponding radial deformation increment decreases significantly. The minimization of the radial deformation increment of the pipe wall restricts the alternating expansion of the internal volume of the flexible air duct body 100. The transient pressure difference increment formed by cold air in the fluid transmission cavity is difficult to be converted into the potential energy of the elastic deformation of the pipe wall. The input fluid pressure wave maintains the initial amplitude and frequency parameters of the input fluid transmission cavity and is directly transmitted along the fluid transmission cavity to the self-excited oscillating pressure-sensitive micropores 104 distributed on the surface of the flexible air duct body 100. The physical process provides a specific structural basis for the functional limitation of avoiding high-frequency pressure attenuation of the fluid.

[0048] The self-excited oscillation pressure-sensitive micropore 104 is embedded in the pipe wall of the flexible air duct body 100. The interior of the self-excited oscillation pressure-sensitive micropore 104 is connected in sequence with a fluid inlet, an alternating deflection chamber and an elastic deformation outlet along the airflow direction. Micro-recirculation cavities are symmetrically arranged on both sides of the alternating deflection chamber.

[0049] When fluid is injected from a narrow channel into a wider cavity, the fluid tends to adhere to the wall on one side. If pressure feedback channels are introduced on both sides of the main flow, the pressure change on the side of the main flow will form a lateral pressure difference through the pressure feedback channels, forcing the main flow to deflect to the other side, thus forming fluid self-excited oscillation. In response to the alternating air pressure generated by the fluid self-excited oscillation, the elastic deformation outlet is made of elastic polymer material and contracts at the end to form a closed slit structure. When the peak of the alternating air pressure arrives, the local high pressure inside the elastic deformation outlet overcomes the elastic contraction force of the slit structure, causing the slit structure to open. When the trough of the alternating air pressure arrives, the slit structure recovers its contracted closed state by relying on the elastic modulus of the material itself. For the specific aerodynamic profile curve design of the fluid oscillator utilizing the wall effect, those skilled in the art can refer to the conventional aerodynamic model of the fluid control element for parameter calibration. The basic profile design of the fluid oscillator utilizing the wall effect is a well-known technology in this field and will not be described in detail here.

[0050] The fluid inlet receives cold air conducted from inside the flexible duct body 100. After entering the alternating deflection chamber, the cold air flows along the wall of the micro recirculation cavity on one side. A portion of the cold air flows back along the micro recirculation cavity to the inlet of the alternating deflection chamber, creating a local high-pressure zone on the side of the main flow. The local high-pressure zone pushes the main flow to deflect towards the micro recirculation cavity on the other side. After the main flow deflects, the same recirculation pressurization process is generated, thus forming a high-frequency alternating deflection airflow in the alternating deflection chamber. When the high-frequency alternating deflection airflow reaches the elastic deformation outlet, a high-frequency alternating air pressure is applied to the internal hole wall of the elastic deformation outlet.

[0051] Under the drive of high-frequency alternating gas pressure, the elastic deformation outlet undergoes high-frequency expansion and contraction deformation. The deformation frequency induced by fluid self-excited oscillation follows the physical equation below:

[0052] ;

[0053] In the formula, This represents the frequency of alternating air pressure generated by the self-excited oscillation of the fluid. The dimensionless Strauhal number represents the oscillatory properties of fluid. This indicates the input velocity of cold air at the fluid inlet. This indicates the characteristic hydraulic diameter of the fluid inlet.

[0054] The high-frequency alternating deflection of the airflow, combined with the periodic physical deformation of the elastic deformation outlet, cuts off the continuously ejected cold air. In macroscopic fluid phenomena, this is manifested as the continuous airflow being blocked by the alternating opening and closing slit structure and squeezed out in the form of discontinuous air masses. The cut-off cold air entrains the still air in the external environment and reconstructs it into discrete aerodynamic vortex rings. The process of using micro recirculation cavities to induce airflow deflection and relying on alternating air pressure to drive the deformation of the elastic deformation outlet is completed.

[0055] See attached document Figure 6 , Figure 6 This is a flowchart of multi-source environmental state acquisition and dew point calculation according to an embodiment of the present invention. This embodiment further illustrates the specific execution process of the sensing and control unit acquiring environmental parameters and calculating transient dew point temperature. In order to acquire micro-environmental parameters, the sensing and control unit includes environmental temperature and humidity sensors distributed in the target operating environment and surface temperature sensors attached to the surface of the target object. The environmental temperature and humidity sensors are used to acquire air temperature data and relative humidity data of the target operating environment in real time, and the surface temperature sensors are used to acquire real-time temperature data of the surface of the target object. For the specific communication protocol and sampling circuit design of the environmental temperature and humidity sensors and the surface temperature sensors, those skilled in the art can refer to existing sensor application manuals for configuration. The data acquisition and communication of the sensors are well known technologies in the field and will not be described in detail here.

[0056] Analyzing the condensation process from the perspective of fluid thermodynamics, when water vapor in the ambient air comes into contact with a solid surface at a lower temperature, if the surface temperature is lower than the dew point temperature of the ambient air under the current conditions, the water vapor releases its latent heat of vaporization and undergoes a phase change on the solid surface, condensing into liquid water. During the process of injecting cold air into the target object for cooling, the surface temperature of the target object will gradually decrease. If no intervention is taken, the surface temperature of the target object will drop below the condensation critical point, causing water droplets to form on the surface, which may lead to short circuits in electronic components or corrosion of metal structural parts. Therefore, in order to avoid the phase change condensation phenomenon induced when cold air enters the target operating environment, the sensing and control unit needs to establish the condensation critical temperature under the current environmental conditions in advance. The sensing and control unit performs nonlinear mapping calculations based on the acquired air temperature data and relative humidity data, and calls the internally stored Magnus empirical formula for logical calculations.

[0057] The physical equations for calculating intermediate environmental variables based on Magnus's empirical formula for the sensing and control unit are as follows:

[0058] ;

[0059] In the formula, This represents intermediate environmental variables calculated based on current air temperature and relative humidity data. This indicates the air temperature data collected by the ambient temperature and humidity sensor. This indicates the relative humidity data collected by the ambient temperature and humidity sensor. This represents the first latent heat of vaporization constant calibrated based on standard atmospheric pressure. This represents the second latent heat of vaporization constant calibrated based on standard atmospheric pressure. Represents the natural logarithm operation.

[0060] After acquiring the intermediate environmental variables, the sensing and control unit further calculates the physical equation for the transient dew point temperature as follows:

[0061] ;

[0062] In the formula, This represents the transient dew point temperature of the target operating environment under the current conditions. The transient dew point temperature reflects the critical temperature value corresponding to the saturation of water vapor in the ambient air. The sensing and control unit transforms discrete physical quantities into direct data indicators for assessing the risk of condensation through the above physical equations, providing a benchmark reference for subsequent control of the amount of cold air injected.

[0063] After obtaining the transient dew point temperature, considering the fluctuations in environmental parameters and the measurement errors of the sensor devices, the sensing and control unit needs to set a safety buffer zone based on the transient dew point temperature. The sensing and control unit, in conjunction with the preset thermophysical parameters of the target object, constructs the anti-condensation safety boundary temperature. The physical equation for establishing the anti-condensation safety boundary temperature by the sensing and control unit is as follows:

[0064] ;

[0065] In the formula, Indicates the safety boundary temperature for preventing condensation. This indicates the transient dew point temperature of the target operating environment under its current condition. This represents the safety margin variable for preventing condensation, set based on the thermophysical parameters of the target object.

[0066] For the evaluation of the thermal properties of the target object, those skilled in the art can refer to the conventional measurement methods for the specific heat capacity and thermal conductivity of materials in heat transfer. The acquisition of material thermal properties is a well-known technology in this field. The sensing and control unit stores the specific heat capacity and thermal conductivity data of the target object. From the perspective of heat transfer principles, objects of different materials and volumes exhibit different temperature change response rates when subjected to cold air impact. When the target object is a sensitive electronic component with a small heat capacity, the temperature drop rate of the small heat capacity object is faster, and the target object is more likely to break through the condensation critical point in a short time. The sensing and control unit assigns a larger value to the anti-condensation safety margin variable. When the target object is a metal structural component with a large heat capacity, the temperature change of the large heat capacity object has obvious hysteresis. The sensing and control unit assigns a smaller value to the anti-condensation safety margin variable.

[0067] After setting the anti-condensation safety boundary temperature, the sensing and control unit continuously compares the real-time temperature data of the target object surface obtained by the surface temperature sensor with the anti-condensation safety boundary temperature. Based on the comparison result, the sensing and control unit generates a low-frequency pulse width modulation signal and sends the low-frequency pulse width modulation signal to the low-frequency high-flow solenoid valve 200. When the downward trend of the real-time temperature data of the target object surface indicates that the real-time temperature data of the target object surface is approaching the anti-condensation safety boundary temperature, the sensing and control unit reduces the duty cycle of the low-frequency pulse width modulation signal or outputs a cutoff level. The low-frequency high-flow solenoid valve 200 responds to the low-frequency pulse width modulation signal and closes, and the low-frequency high-flow solenoid valve 200 stops injecting cold air into the flexible air duct body 100.

[0068] During the period when the low-frequency high-flow solenoid valve 200 is in the closed state, the heat generated inside the target object is conducted outward to the surface of the target object. The target object uses its own internal heat and thermal inertia to gradually raise the surface temperature of the target object. The surface temperature of the target object rises again and moves away from the anti-condensation safety boundary temperature, which destroys the thermodynamic conditions required for water molecules in the ambient air to condense into liquid water on the surface of the target object. When the real-time temperature data of the target object surface rises and leaves the anti-condensation risk range, the sensing and control unit increases the duty cycle of the low-frequency pulse width modulation signal. The low-frequency high-flow solenoid valve 200 responds to the low-frequency pulse width modulation signal and reopens. The system resumes injecting cold air into the flexible air duct body 100. By adjusting the conduction and cut-off states of the low-frequency high-flow solenoid valve 200 through the sensing and control unit, a dynamic balance between the cold air injection volume and the anti-condensation safety boundary is achieved.

[0069] When the low-frequency high-flow solenoid valve 200 performs start-stop action according to the low-frequency pulse width modulation signal sent by the sensing and control unit, the continuous cold air introduced at the cold source inlet is periodically cut off and connected at the output end of the low-frequency high-flow solenoid valve 200, forming a fluid pressure wave that changes stepwise with time and is input into the flexible air duct body 100.

[0070] In conventional flexible pipelines, the elastic deformation of the pipe wall is equivalent to the aerodynamic capacitance in the fluid network. If the pipeline expands when receiving internal pressure, the gas volume entering the pipeline will preferentially fill the extra space created by the expansion, rather than immediately transmitting pressure forward. When the fluid pressure wave propagates in the pipeline, it will consume some pressure potential energy to expand the pipe wall, resulting in time lag and amplitude attenuation of the rising edge of the fluid pressure. This causes the pressure waveform, which originally had a high pressure gradient, to become a slowly rising state. The flexible duct body 100 is equipped with a radial constraint layer 102 composed of non-stretchable fiber bundles. The radial constraint layer 102 restricts the increase of the internal volume of the flexible duct body 100 as the fluid pressure rises, thereby reducing the aerodynamic capacitance value of the flexible duct body 100.

[0071] The pressure build-up time constant of the fluid pressure wave propagating inside the flexible duct body 100 follows the following physical equation:

[0072] ;

[0073] In the formula, This represents the time constant required for the internal pressure of the fluid transfer chamber to rise to a steady-state value. This indicates the aerodynamic resistance generated along the flow path of the fluid transmission cavity in response to the flow of cold air; This refers to the comprehensive aerodynamic capacitance determined by the elastic characteristics of the pipe wall of the flexible duct body 100.

[0074] Because the radial constraint layer 102 restricts the radial expansion of the flexible duct body 100 wall, the value of the integrated aerodynamic capacitance is reduced, which shortens the time constant required for the air pressure to rise to a steady state value. The fluid pressure wave overcomes the pressure rise hysteresis phenomenon present in the flexible pipe. The square wave cold air output by the low-frequency high-flow electromagnetic valve 200 can maintain the initial pressure rise along the gradient and be conducted along the flexible duct body 100 to the self-excited oscillating pressure-sensitive micro-hole 104. The coordination mechanism between the structural features of the flexible duct body 100 and the fluid dynamic features helps to enable the fluid pressure reaching the self-excited oscillating pressure-sensitive micro-hole 104 to quickly reach the pressure threshold that triggers the airflow deflection in the micro-backflow cavity inside the self-excited oscillating pressure-sensitive micro-hole 104. This reduces the risk that the self-excited oscillating pressure-sensitive micro-hole 104 cannot generate high-frequency alternating air pressure due to slow pressure rise, which is conducive to realizing the transmission of low-frequency electromagnetic control signals to fluid kinetic energy.

[0075] In the general principles of mechanics and heat transfer, when a continuous flow of cold air blows onto the surface of a heated object, a slow-flowing air layer with a temperature gradient is formed between the air flow and the object's surface due to the viscous force of the air. This air layer is called the thermal boundary layer. The thermal boundary layer constitutes a fluid resistance layer that hinders heat transfer. The thermal boundary layer slows down the heat exchange process between the cold air and the object's surface, thus limiting the cooling efficiency of continuous airflow. For the calculation of the convective heat transfer coefficient and the assessment of the thermal boundary layer thickness, those skilled in the art can refer to the conventional fluid dynamics models in the heat transfer handbook for estimation. The basic theory of convective heat transfer is a well-known technology in this field and will not be elaborated here.

[0076] Based on the aforementioned structural action logic, the self-excited oscillating pressure-sensitive micro-orifice 104 undergoes high-frequency opening and closing deformation in response to the alternating air pressure inside the flexible air duct body 100. The continuously input cold air is physically cut off at the self-excited oscillating pressure-sensitive micro-orifice 104 by the high-frequency opening and closing slit structure. The discontinuous cold air mass squeezed out entrains the surrounding still air when it exits the boundary of the self-excited oscillating pressure-sensitive micro-orifice 104. Due to the entrainment effect, the fluid tumbles and is reconstructed into a discrete aerodynamic vortex ring with spin motion characteristics. The aerodynamic vortex ring maintains the stability of the fluid structure inside the aerodynamic vortex ring by relying on its own spin characteristics, reducing the kinetic energy dissipation during the movement of the aerodynamic vortex ring towards the surface of the target object. The initial impulse of the aerodynamic vortex ring when it leaves the self-excited oscillating pressure-sensitive micro-orifice 104 follows the following physical equation:

[0077] ;

[0078] In the formula, This represents the initial impulse of the aerodynamic vortex ring; This indicates the density of the cold air inside the flexible air duct body 100. This represents the equivalent spray area of ​​the self-excited oscillating pressure-sensitive micropore 104 in the open state; This indicates the instantaneous flow velocity of cold air ejected from the self-excited oscillating pressure-sensitive micro-orifice 104; This indicates the duration of a single expansion state of the self-excited oscillating pressure-sensitive micropore 104.

[0079] The high-frequency cut-off action concentrates the kinetic energy of the cold air continuously input into the flexible air duct body 100 into the duration of a single expansion state of the self-excited oscillating pressure-sensitive micropore 104. The concentrated kinetic energy release process gives the aerodynamic vortex ring instantaneous momentum. When the aerodynamic vortex ring impacts the surface of the target object, the initial impulse contained in the aerodynamic vortex ring helps the aerodynamic vortex ring to destroy the thermal boundary layer attached to the surface of the target object. The cold air inside the aerodynamic vortex ring directly scours the surface of the target object, which is beneficial to improving the convective heat transfer efficiency between the cold air and the surface of the target object. The above process of converting the continuous airflow into a discrete vortex ring and destroying the thermal boundary layer avoids relying on external mechanical mechanisms for high-frequency forced air delivery, and relies on the mutual cooperation between the flexible air duct body 100 and the internal flow channel structure of the self-excited oscillating pressure-sensitive micropore 104.

[0080] Because the flexible air duct body 100 has the characteristics of bendable material, the flexible air duct body 100 can be suspended and deployed above the target object to form a suspended form, or directly attached to the narrow space inside the target object to form an embedded form. For the identification of the installation form and the acquisition of distance, those skilled in the art can use manual input of configuration parameters or deployment of distance measuring sensors to acquire distance parameters. The measurement and acquisition of spatial distance parameters are well known technologies in the field and will not be described in detail in the specification.

[0081] The sensing and control unit stores a preset distance judgment threshold. The sensing and control unit obtains the actual installation distance between the self-excited oscillating pressure-sensitive micro-hole 104 on the flexible air duct body 100 and the surface of the target object, and compares the actual installation distance with the preset distance judgment threshold. When the actual installation distance is greater than the preset distance judgment threshold, the sensing and control unit determines that the flexible air duct body 100 is in a suspended working mode. In the suspended working mode, the aerodynamic vortex ring ejected from the self-excited oscillating pressure-sensitive micro-hole 104 needs to cross a long free air space to reach the surface of the target object. The aerodynamic vortex ring will experience kinetic energy and impulse attenuation when flying in the ambient air. When the actual installation distance is less than or equal to the preset distance judgment threshold, the sensing and control unit determines that the flexible air duct body 100 is in an embedded working mode. In the embedded working mode, the self-excited oscillating pressure-sensitive micro-hole 104 is close to the surface of the target object, and the ejection flight distance of the aerodynamic vortex ring is shorter. If the same fluid momentum output is maintained as in long-distance flight, the concentrated cold flow impact can easily cause local overcooling of the target object surface, increasing the risk of inducing the anti-condensation safety boundary alarm.

[0082] To adaptively match the suspended and embedded operating modes, the sensing and control unit dynamically schedules the control parameters of the low-frequency, high-flow solenoid valve 200 based on the actual installation distance. From a fluid dynamics perspective, extending the valve's on-time allows more mass of cold air to be injected into the flexible duct body 100, thereby establishing a higher peak back pressure before the self-excited oscillating pressure-sensitive micro-orifice 104 opens, thus increasing the initial momentum of the ejected vortex ring. The physical equation for calculating the valve opening compensation time by the sensing and control unit is as follows:

[0083] ;

[0084] In the formula, This indicates the compensated opening time of the sensing and control unit for the output of the low-frequency, high-flow solenoid valve 200; This indicates the basic on-time of the sensing and control unit, determined based on environmental heat dissipation requirements. This indicates the actual installation distance between the self-excited oscillating pressure-sensitive micro-hole 104 and the surface of the target object; This indicates the preset distance threshold used to distinguish between the suspension-type working mode and the embedded working mode; This represents the momentum dissipation compensation coefficient calibrated based on the degree of external environmental airflow interference.

[0085] Based on the equation, a scheduling support relationship is established. When the flexible duct body 100 is in the suspended working mode, the actual installation distance is greater than the preset distance judgment threshold, the proportional term in the equation is positive, the compensation opening time is greater than the basic opening time, and the sensing and control unit controls the low-frequency high-flow electromagnetic valve 200 to extend the single conduction time, so that the fluid pressure inside the flexible duct body 100 accumulates higher, giving the aerodynamic vortex ring ejected from the self-excited oscillating pressure-sensitive micro-hole 104 a larger initial impulse, which helps to offset the momentum dissipation of the aerodynamic vortex ring during long-distance flight. When the flexible duct body 100 is in the embedded working mode, the actual installation distance is less than or equal to the preset distance judgment threshold, the proportional term in the equation is negative or zero, the compensation opening time is less than or equal to the basic opening time, and the sensing and control unit controls the low-frequency high-flow electromagnetic valve 200 to shorten the single conduction time, reducing the initial impulse of the aerodynamic vortex ring, so that the impact action of the aerodynamic vortex ring on the surface of the target object tends to be milder. The mode judgment and parameter adjustment mechanism provides an algorithm execution basis for adaptive adjustment of fluid momentum under different installation distances.

[0086] When the target object is in the form of a column or cable, the flexible air duct body 100 can follow the surface contour of the target object to make multiple spiral windings to form a vortex tube working mode. For obtaining the winding curvature of the flexible air duct body 100, those skilled in the art can use flexible strain sensor devices or manually input geometric parameters. The measurement and acquisition of curvature parameters are well known technologies in the field and will not be described in detail in the specification.

[0087] In the vortex tube operating mode, multiple self-excited oscillating pressure-sensitive micro-holes 104 distributed on the flexible air duct body 100 are arranged in an inward ring array. From the perspective of multi-source jet interference principle, if multiple adjacent self-excited oscillating pressure-sensitive micro-holes 104 continuously spray aerodynamic vortex rings at high frequency in a closed annular space, the flow field of the entrainment area of ​​adjacent aerodynamic vortex rings is prone to overlap, causing the aerodynamic vortex rings to collide and break before impacting the surface of the target object. This affects the effect of the aerodynamic vortex rings in penetrating the thermal boundary layer and increases the risk of forming a closed fluid stagnation zone around the target object and hindering the outward escape of hot air. In order to reduce the flow field interference risk caused by the ring array spray, the sensing and control unit needs to dynamically adjust the operating frequency of the low-frequency high-flow electromagnetic valve 200 according to the winding curvature radius of the flexible air duct body 100 to control the generation density of the aerodynamic vortex rings. The physical equation for the sensing and control unit to calculate the anti-interference critical pulse spray frequency is as follows:

[0088] ;

[0089] In the formula, This indicates the critical pulse jet frequency for interference prevention. This indicates the instantaneous flow velocity of cold air ejected from the self-excited oscillating pressure-sensitive micro-orifice 104. Represents pi (π). This represents the actual radius of curvature of the flexible air duct body spirally wound around the surface of the target object. This represents the interference avoidance coefficient calibrated based on the dimensionless Strauhal number of the fluid.

[0090] When the sensing and control unit determines that the flexible duct body 100 is in vortex tube working mode, the actual radius of curvature decreases as the number of winding turns of the flexible duct body 100 increases or the diameter of the target object decreases. This causes a change in the calculated value of the anti-interference critical pulse jet frequency. The sensing and control unit clamps the upper limit of the pulse width modulation working frequency of the low-frequency high-flow solenoid valve 200 within the range of the anti-interference critical pulse jet frequency. When the calculated anti-interference critical pulse jet frequency decreases, the sensing and control unit controls the low-frequency high-flow solenoid valve 200 to extend the valve section. During the idle period in the closed state, the spiral winding structure of the flexible air duct body 100 forms a restricted heat dissipation channel on the surface of the target object. Lengthening the time interval between two adjacent aerodynamic vortex ring injections can weaken the hydrodynamic blocking effect of the high-frequency jet airflow on the heat dissipation channel. This allows physical time for the preceding jet of cold air to absorb heat and diffuse outward from the spiral gap. It helps to reduce the collision and mixing between the newly generated cold air vortex ring and the stagnant hot air. The frequency clamping and idle period extension mechanism are conducive to forming a heat dissipation scheduling strategy that adapts to the narrow columnar space.

[0091] When the target object is a large-area flat or curved shell, the flexible air duct body 100 can be laid flat or in a grid-like manner on the equipment shell to form an adhesive working mode. For the acquisition of the surface temperature and heating state of the equipment shell, those skilled in the art can use temperature sensors or read the power consumption data of the equipment operation. The measurement and acquisition of temperature and heating state are well known technologies in the field and will not be described in detail in the specification.

[0092] In the application mode, the self-excited oscillating pressure-sensitive micro-holes 104 distributed on the flexible air duct body 100 are close to the surface of the equipment shell. From the perspective of wall jet theory in heat transfer and fluid mechanics, large-area equipment shells usually have large structural heat capacity and two-dimensional lateral heat conduction capacity. After the aerodynamic vortex ring is ejected from the self-excited oscillating pressure-sensitive micro-holes 104, it will impact the surface of the equipment shell and undergo radial deflection at the stagnation point, transforming into a wall jet that diffuses in all directions along the surface of the equipment shell. The wall jet carries away heat by scouring the surface of the equipment shell. Since the metal equipment shell has obvious thermal inertia, if the energy density of the input cold air does not match the dynamic heat flux of the equipment shell, it is easy to cause local thermal stress concentration. In order to adapt to the thermophysical characteristics of the equipment shell, the sensing and control unit needs to dynamically adjust the pulse width modulation duty cycle of the low-frequency high-flow electromagnetic valve 200 according to the real-time thermal state of the equipment shell, thereby controlling the average mass flow rate of the cold air input to the flexible air duct body 100.

[0093] The physical equation for calculating the target value of the patch duty cycle in the sensing and control unit is as follows:

[0094] ;

[0095] In the formula, This represents the target duty cycle value for the application type calculated by the sensing and control unit for the low-frequency, high-flow solenoid valve 200. This represents the steady-state basic heat dissipation power of the equipment casing. This indicates the specific heat capacity of the equipment casing material. This indicates the equivalent heat transfer mass of the equipment casing. This indicates the real-time rate of temperature change on the surface of the device's casing. This indicates the density of the cold air inside the flexible air duct body 100. This indicates the instantaneous flow velocity of cold air ejected from the self-excited oscillating pressure-sensitive micro-orifice 104. This represents the equivalent spray area of ​​the self-excited oscillating pressure-sensitive microorifice 104 in the open state. This represents the specific heat capacity at constant pressure of cold air. This indicates the real-time surface temperature of the device casing. This indicates the temperature of the cold air input into the flexible air duct body 100. This represents the heat transfer coupling coefficient of the coating, calibrated based on the wall jet expansion area.

[0096] When the sensing and control unit determines that the flexible duct body 100 is in the application mode, it calculates the required dynamic heat compensation based on the steady-state basic heat dissipation power and surface temperature change rate of the equipment shell. When the heat load on the equipment shell increases, resulting in a positive real-time temperature change rate and an increase in value, the calculated application duty cycle target value increases accordingly. The sensing and control unit controls the low-frequency high-flow solenoid valve 200 to increase the proportion of its conduction time within a single control cycle, increasing the number of aerodynamic vortex rings generated per unit time and the total mass flow rate of cold air, thus enhancing the wall jet's ability to scour and cool the surface of the equipment shell. When the heat load on the equipment shell decreases, resulting in a decrease in the real-time temperature change rate... When the rate of change is negative or close to zero, the sensing and control unit controls the low-frequency high-flow solenoid valve 200 to reduce the pulse width modulation duty cycle based on the decreasing target value of the applied duty cycle. Reducing the pulse width modulation duty cycle can prolong the gap period of cold air cutoff. During the gap period, the heat inside the equipment shell can be transferred laterally to the cooled stagnation area, which helps to smooth out the local temperature difference and reduce the energy density of the cold air input. The duty cycle dynamic adjustment mechanism utilizes the thermal inertia of the equipment shell itself to buffer the cooling capacity, which helps to weaken the local quenching effect generated by the discrete aerodynamic vortex ring near the impact point. This is beneficial to maintaining the temperature uniformity of a large area of ​​the shell while achieving a dynamic balance of overall heat dissipation energy.

[0097] Specific application examples:

[0098] To further verify the cooling efficiency, anti-condensation safety, and adaptive scheduling effectiveness of the flexible microporous cold air cooling system and its heat dissipation structure proposed in this invention under different deployment environments, three typical application scenarios were constructed based on the structural principles and control logic of the specific implementation method, and combined with the appendix... Figure 5 Appendix Figure 6 and attached Figure 7 The data shown will be explained in detail.

[0099] In the application scenario of this embodiment, the flexible microporous cold air cooling system performs dynamic control strategy adjustments for target objects with different thermal properties and installation forms.

[0100] Data acquisition and experimental setup implementation:

[0101] To ensure the objectivity of the experimental data and the accuracy of the verification charts, the sensing and control unit first performed the following data preparation work:

[0102] The system is configured with uniform cold source input conditions, with the cold air input temperature stabilized at 15℃, the initial air temperature of the target operating environment set at 30℃, and the relative humidity set at 60%. The sensing and control unit calculates the transient dew point temperature in real time based on the Magnus empirical formula and sets corresponding anti-condensation safety boundary temperatures in combination with the heat capacity characteristics of different target objects.

[0103] Appendix Figure 5 To be continued Figure 7 The curves and bar charts in the chart represent surface temperature data, control parameter commands, and heat exchange efficiency calculations captured in real time by the sensing and control units.

[0104] Example 1: Cooling the outer casing of a patch-type device

[0105] The flexible air duct body 100 is attached to the surface of the equipment shell in the computer room in a grid pattern. The micro-holes blow air outwards towards the equipment shell to cool the entire shell. This method is suitable for equipment that should not be in close contact with its interior.

[0106] Implementation of thermophysical property regulation using adhesive application:

[0107] In the application mode, to verify the system's ability to cool the casing of large heat capacity equipment uniformly and avoid localized quenching, the sensing and control unit dynamically adjusted the duty cycle of the low-frequency, high-flow electromagnetic valve 200.

[0108] Experimental setup: The outer casing of the equipment experienced a sudden high internal heat load at the 10th minute, causing a sharp increase in the basic heating power. The heat load returned to normal at the 40th minute.

[0109] Experimental execution process: The sensing and control unit acquires the ambient air temperature and relative humidity of the computer room in real time through environmental temperature and humidity sensors. The transient dew point temperature is calculated based on the Magnus empirical formula, and the corresponding anti-condensation safety boundary temperature is set in combination with the large heat capacity characteristics of the equipment shell.

[0110] During operation, the surface temperature sensor monitors the surface temperature of the equipment casing in real time. When the heat increases sharply at the 10th minute, the sensing and control unit obtains the positive and rapidly increasing surface temperature change rate. Then, it calls the preset thermophysical parameters such as the specific heat capacity and equivalent heat transfer mass of the equipment casing material, substitutes them into the physical equation of the target value of the application duty cycle, and performs nonlinear mapping calculation. After calculating the required duty cycle, the sensing and control unit generates the corresponding low-frequency pulse width modulation signal and sends it to the low-frequency high-flow solenoid valve 200.

[0111] The low-frequency, high-flow electromagnetic valve 200 responds to a high duty cycle signal, increasing the conduction time and allowing cold air to enter the fluid transmission chamber in a high-frequency step manner. Under the action of the radial constraint layer 102, the pressure wave is rapidly and axially transmitted without hysteresis to the self-excited oscillating pressure-sensitive micro-holes 104 arranged in a grid pattern. The micro-holes are forced to undergo high-frequency deformation, cutting out a large number of aerodynamic vortex rings. After the aerodynamic vortex rings impact the surface of the equipment shell, they undergo stagnation point deflection, transforming into wall jets that diffuse and scour heat along the surface. At the 40th minute, the heat load is unloaded, and the surface temperature change rate turns negative. The sensing and control unit adjusts the target value of the applied duty cycle according to the equation calculation results, shortening the valve conduction time and using the thermal inertia of the equipment shell itself to suppress local temperature differences.

[0112] Data analysis: by Figure 5 Data details are available, see attached. Figure 5 The left vertical axis represents the real-time surface temperature of the equipment casing (°C), the right vertical axis represents the system output duty cycle (%), and the horizontal axis represents the running time (minutes). During the stable period from 0 to 10 minutes, the equipment casing temperature remains around 35°C, and the system operates at a low duty cycle of 30%. After a sudden increase in heat load in the 10th minute, the surface temperature rises rapidly. The sensing and control unit monitors the positive temperature change rate in real time and, based on the physical equation of the target duty cycle value for adhesive application, quickly increases the duty cycle to 80%. Figure 5 Above the right axis, as a large number of aerodynamic vortex rings scour the outer shell, the surface temperature reaches its peak at the 20th minute and then begins to decline steadily. After the heat load is unloaded at the 40th minute, the system actively lowers the duty cycle to the 20% sleep level, using the thermal inertia of the outer shell itself to suppress the temperature and prevent the temperature from falling below the anti-condensation safety boundary.

[0113] Conclusion: The examples demonstrate that the system can effectively utilize the thermal conductivity inertia of the target object for cooling buffering in the application mode, achieving precise matching between heat dissipation energy and dynamic heat flux of a large-area shell.

[0114] Example 2: Point-to-point cooling of suspension components

[0115] The flexible air duct body 100 is suspended and installed directly above the high-temperature heating element, with a distance of 2.5cm between it and the element. The micro-holes blow air into the element to achieve targeted strong cooling without contact or short circuit.

[0116] Implementation of suspension-based impulse attenuation avoidance:

[0117] In the suspension-type working mode, due to the long injection distance, the aerodynamic vortex ring is prone to momentum decay in free space. To verify the effectiveness of the system in compensating for the start-up time scheduling based on the installation distance, a comparison of the fixed-point convection heat transfer effect was conducted.

[0118] Experimental setup: The traditional continuous blowing mode, the fixed pulse mode without distance compensation, and the dynamic duration compensation mode based on distance feedback proposed in this invention were compared.

[0119] Experimental execution process: In the dynamic duration compensation mode based on distance feedback, the sensing and control unit first obtains that the actual installation distance between the self-excited oscillating pressure-sensitive micro-hole 104 on the flexible air duct body 100 and the surface of the high-temperature heating element is 2.5cm. The sensing and control unit compares this distance with the preset distance judgment threshold, confirms that the actual distance is greater than the threshold, and determines that the system is currently in the suspension working mode.

[0120] The sensing and control unit uses the momentum dissipation compensation coefficient calibrated by the degree of airflow interference in the external environment as input, and calculates the positive compensation opening time based on the physical equation of valve opening compensation time. The sensing and control unit adjusts the low-frequency pulse width modulation signal according to the total compensation time, instructing the low-frequency high-flow solenoid valve 200 to extend the conduction time in a single action cycle. During the extended conduction period, the mass of cold air filling the fluid transmission cavity of the flexible air duct body 100 increases, and because the radial constraint layer 102 restricts the expansion volume of the pipe wall, the fluid rapidly accumulates during this period, forming an extremely high peak back pressure.

[0121] When the step pressure wave is transmitted to the micropore, the high pressure difference drives the cold air to be injected at high speed into the alternating deflection chamber in the self-excited oscillating pressure-sensitive micropore 104. The elastic deformation outlet is forced to open under high pressure, squeezing out the large initial impulse of the aerodynamic vortex ring, overcoming the kinetic energy dissipation in the 2.5cm free air space. Finally, the aerodynamic vortex ring directly impacts and destroys the fluid resistance layer on the surface of the component with high initial momentum.

[0122] Data analysis: by Figure 6 Data details are available, see attached. Figure 6 The horizontal axis in the figure represents different control strategies, and the vertical axis represents the peak convective heat transfer coefficient (W / (m²)) measured at the target surface. 2In the traditional continuous blowing mode, the convective heat transfer coefficient is only 42.5 due to the obstruction of the thermal boundary layer. Although the fixed pulse mode generates aerodynamic vortex rings, the momentum of the vortex rings has significantly decreased by the time they reach the surface because the suspension distance (2.5cm) exceeds the default threshold, and the heat transfer coefficient only increases to 58.3. However, after the system of this invention determines that it is currently in suspension mode, it extends the single conduction time according to the compensation equation. After establishing a higher initial back pressure, the aerodynamic vortex rings ejected from the micro-holes have extremely high initial impulse, successfully penetrating the thermal boundary layer on the surface of the component. The convective heat transfer coefficient jumps to 86.7, which is significantly higher than the former two.

[0123] Conclusion: The implementation example verifies that the system can adaptively identify the suspension distance and impart higher initial momentum to the fluid by compensating for the valve opening time, thus solving the problem of kinetic energy dissipation over long distances.

[0124] Example 3: Embedded cooling on one side of the PCB integration

[0125] The flexible air duct body 100 is embedded in a small space on one side of the PCB board, forming an integrated mold with the equipment without occupying extra space, thus achieving concealed and uniform cooling.

[0126] Flow field avoidance and frequency clamping implementation:

[0127] In a confined space, high-frequency jetting can easily cause flow field overlap and interference between adjacent holes and rapidly drop below the dew point, leading to condensation. To verify the effect of adjusting the critical pulse jetting frequency of the system in preventing interference, the PCB cooling process was monitored.

[0128] Experimental setup: Simulate PCB chip operating under high load, compare two sets of curves: fixed high frequency pulse (avoidance not enabled) and frequency clamping scheduling (this invention). The ambient transient dew point temperature is calculated to be 18℃, and the anti-condensation safety boundary temperature is set to 20℃.

[0129] Experimental Execution Process: Under the frequency clamping scheduling strategy, the system was concealed and deployed in a narrow space. The sensing and control unit detected that the flexible air duct body 100 was embedded in a space with limited height and obtained the equivalent local radius of curvature. Substituting parameters such as the interference avoidance coefficient and instantaneous flow velocity, the sensing and control unit calculated the upper limit of the maximum allowable jet frequency of the system based on the physical equation of the anti-interference critical pulse jet frequency.

[0130] The sensing and control unit clamps the operating frequency of the low-frequency pulse width modulation signal sent to the low-frequency high-flow solenoid valve 200 below the critical frequency, forcibly extending the idle period of the low-frequency high-flow solenoid valve 200 in the closed state.

[0131] During system operation, the low-frequency, high-flow electromagnetic valve 200 sparsely performs start-stop actions. The aerodynamic vortex ring jet density generated within the flexible duct body 100 is controlled to decrease. Simultaneously, the sensing and control unit continuously compares the chip surface temperature collected in real time by the surface temperature sensor with the 20°C anti-condensation safety boundary temperature. If excessively rapid cooling is detected and there is a risk of breaking the boundary, the duty cycle is further fine-tuned to reduce cooling. During the process, the preceding aerodynamic vortex ring penetrates the thermal boundary layer to absorb heat. The controlled extended idle period provides sufficient physical time for the heat-absorbing trapped air to dissipate outward from the embedded narrow gap, avoiding collisions and flow field overlap interference between multi-source jets in the confined space.

[0132] Data analysis: by Figure 7 As can be seen, the appendix Figure 7 The horizontal axis represents time (seconds), and the vertical axis represents the chip surface temperature (°C). When using a fixed high-frequency pulse, the initial temperature drops rapidly, reaching 22°C in the 30th second. However, due to the excessively dense jetting, a fluid stagnation zone forms in the narrow space, hindering the dissipation of hot air. This causes the temperature to rebound and oscillate around 25°C. Between 25 and 30 seconds, there is a risk of a localized momentary approach to the 20°C dew point threshold. However, after activating the frequency clamping mechanism, this system extends the idle period of the valve closure, allowing time for heat to diffuse outward while effectively breaking down the thermal boundary layer. The chip temperature exhibits a gradual, gradient-like downward trend, eventually stabilizing at a safe level around 26°C, without any rapid cooling approaching the 20°C anti-condensation boundary.

[0133] Conclusion: The examples demonstrate that by limiting the maximum jet frequency, heat dissipation blockage caused by multi-source jet interference is avoided, while the continuous cold input is cut off by relying on a low duty cycle, thus avoiding the risk of water droplet condensation on the PCB surface.

Claims

1. A flexible microporous cold air cooling system, characterized in that, include: Cold source inlet, wherein cold air is introduced; A flexible air duct body (100) has self-excited oscillating pressure-sensitive micropores (104) spaced apart on its surface. A low-frequency, high-flow-rate solenoid valve (200) is connected to the cold source inlet and the flexible duct body (100). The sensing and control unit is used to collect air temperature data, relative humidity data and real-time temperature data of the target object surface, calculate the anti-condensation safety boundary temperature, and compare the real-time temperature data with the anti-condensation safety boundary temperature to generate a low-frequency pulse width modulation signal to control the opening and closing of the low-frequency high-flow electromagnetic valve (200). When the low-frequency high-flow electromagnetic valve (200) is opened, cold air enters the flexible air duct body (100). The self-excited oscillating pressure-sensitive micropore (104) undergoes high-frequency expansion and contraction deformation under the action of alternating air pressure generated by the self-excited oscillation of the fluid, cutting the cold air into aerodynamic vortex rings and spraying it onto the surface of the target object.

2. The flexible microporous cold air cooling system according to claim 1, characterized in that, The flexible air duct body (100) is provided with an airtight inner liner (101), a radial constraint layer (102) and an outer protective sleeve (103) in sequence from the inside to the outside along the radial section. The airtight inner liner (101) defines the fluid transmission cavity. The radial constraint layer (102) is composed of multiple non-stretchable fiber bundles woven together. The outer protective sleeve (103) is made of porous foam material with interconnected micropores throughout.

3. The flexible microporous cold air cooling system according to claim 1, characterized in that, The self-excited oscillation pressure-sensitive micropore (104) has a fluid inlet, an alternating deflection chamber and an elastic deformation outlet connected sequentially along the airflow direction. The alternating deflection chamber has micro-recirculation cavities symmetrically arranged on both sides. After cold air enters the alternating deflection chamber, it flows back along the micro-recirculation cavity to drive the main stream to deflect alternately, thus forming the fluid self-excited oscillation.

4. The flexible microporous cold air cooling system according to claim 3, characterized in that, The elastic deformation outlet contracts at its end to form a closed slit structure, which is opened and closed at high frequency under the action of the alternating air pressure.

5. The flexible microporous cold air cooling system according to claim 1, characterized in that, The specific method for calculating the safety boundary temperature for preventing condensation is as follows: Intermediate environmental variables are calculated based on the collected air temperature data and relative humidity data; The transient dew point temperature is calculated based on the aforementioned intermediate environmental variables; By combining the transient dew point temperature with the anti-condensation safety margin variable set based on the thermal property parameters of the target object, the anti-condensation safety boundary temperature is calculated by adding the transient dew point temperature to the anti-condensation safety margin variable.

6. The flexible microporous cold air cooling system according to claim 5, characterized in that, The specific method for generating a low-frequency pulse width modulation signal by comparing the real-time temperature data with the anti-condensation safety boundary temperature is as follows: When the downward trend of the real-time temperature data indicates that the real-time temperature data is approaching the anti-condensation safety boundary temperature, the sensing and control unit reduces the duty cycle of the low-frequency pulse width modulation signal or outputs a cutoff level to control the low-frequency high-flow electromagnetic valve (200) to close.

7. The flexible microporous cold air cooling system according to claim 6, characterized in that, When the real-time temperature data rises and leaves the anti-condensation risk zone, the sensing and control unit increases the duty cycle of the low-frequency pulse width modulation signal and controls the low-frequency high-flow electromagnetic valve (200) to open.

8. The flexible microporous cold air cooling system according to claim 1, characterized in that, The sensing and control unit acquires the actual installation distance between the self-excited oscillating pressure-sensitive micropores on the flexible air duct body and the surface of the target object. The sensing and control unit compares the actual installation distance with a preset distance determination threshold. When the actual installation distance is greater than the preset distance judgment threshold, the sensing and control unit determines that the flexible air duct body (100) is in the suspension working mode. When the actual installation distance is less than or equal to the preset distance determination threshold, the sensing and control unit determines that the flexible air duct body (100) is in the embedded working mode. The sensing and control unit calculates the compensated opening time of the low-frequency high-flow solenoid valve (200) based on the actual installation distance.

9. The flexible microporous cold air cooling system according to claim 8, characterized in that, The sensing and control unit calculates the compensated opening time of the low-frequency high-flow solenoid valve (200) based on the actual installation distance as follows: When the flexible air duct body (100) is in the suspension working mode, the compensation opening time is greater than the basic opening time, and the sensing and control unit controls the low frequency high flow electromagnetic valve (200) to extend the single conduction time. When the flexible air duct body (100) is in the embedded working mode, the compensation opening time is less than or equal to the basic opening time, and the sensing and control unit controls the low-frequency high-flow electromagnetic valve (200) to shorten the single conduction time.

10. A flexible microporous cooling and heat dissipation structure, characterized in that, The flexible microporous cold air cooling system according to any one of claims 1-9 comprises: A multi-layer composite tubular flexible air duct body (100) is provided with an airtight inner liner layer (101), a radial constraint layer (102) and an outer protective sleeve (103) in a radial section from the inside to the outside. The airtight inner liner layer (101) is made of thermoplastic polyurethane elastomer material and defines a fluid transmission cavity inside. The radial constraint layer (102) covers the outer circumferential surface of the airtight inner liner layer (101). The radial constraint layer (102) is formed by multiple non-stretchable fiber bundles interlaced in a large braiding angle spiral winding manner to form network nodes. The outer protective sleeve (103) is attached and fixed to the outside of the radial constraint layer (102). The outer protective sleeve (103) is made of porous foam material with interconnected micropores inside. Multiple self-excited oscillating pressure-sensitive micropores (104) are embedded in the pipe wall of the flexible air duct body (100). The interior of each self-excited oscillating pressure-sensitive micropore (104) is sequentially connected along the airflow direction to a fluid inlet for receiving cold air from the fluid transmission chamber, an alternating deflection chamber, and an elastic deformation outlet. The alternating deflection chamber has micro-recirculation cavities symmetrically arranged on both sides. The elastic deformation outlet is made of elastic polymer material and forms a closed slit structure at the end.

Images