An optimal design method of filter element for aviation liquid-cooled electronic equipment

Abstract

The application discloses an optimal design method of a filter core for aviation liquid-cooled electronic equipment, and comprises the following steps: step 1, generating an initial population through a chromosome structure; step 2, calculating a filter core folding angle number; step 3, calculating a filter core filtering speed and a filter core total mass, and judging whether the filter core filtering speed and the filter core total mass meet filter core filtering speed constraints and filter core total mass constraints; step 4, calculating a filter core flow resistance according to a Darcy law, and judging whether the filter core flow resistance meets filter core flow resistance constraints; step 5, calculating a filter core life function; step 6, selecting a chromosome with the highest life function in a current generation population, and the filter core outer diameter, the filter core folding wave number, the filter core folding height, the filter core filtering surface height and the filter core filtering surface thickness in the chromosome are optimal configurations, and the optimal design of the filter core is completed. The application can directly give the filter core structure parameter configuration with the highest life.

Description

Technical Field

[0001] This invention relates to the field of aviation liquid-cooled electronic equipment technology, and specifically to an optimal design method for filter elements used in aviation liquid-cooled electronic equipment. Background Technology

[0002] With the continuous improvement of the integration and heat flux density of integrated avionics systems, liquid cooling has become one of the most widely used cooling methods for avionics equipment. During service, avionics liquid-cooled electronic equipment will generate a certain amount of impurities in the cooling medium due to internal and external factors within the flow channels. When the contamination level of the cooling medium exceeds the contamination tolerance level of the fluid connector, issues such as… Figure 3 The phenomena of seepage and leakage shown can, in severe cases, lead to catastrophic events such as circuit burnout and equipment failure, seriously threatening the reliability and safety of aviation liquid-cooled electronic equipment.

[0003] The installation of filter elements effectively solves and prevents the aforementioned problems of leakage and seepage caused by contamination in aviation liquid-cooled electronic equipment. For filter elements used in aviation liquid-cooled electronic equipment, in addition to meeting the requirements for filtration accuracy and environmental adaptability, the optimal filter element often needs to have the longest service life while meeting the specific constraints of volume, weight, and flow resistance requirements of aviation platforms. However, due to a lack of effective design methods, filter element design often involves a significant amount of time spent on iterative "adjustment-simulation" processes to meet requirements for volume, weight, and flow resistance, without necessarily achieving optimal service life. This significantly limits the design efficiency of filter elements for aviation liquid-cooled electronic equipment and the maintenance cycle of the equipment. Summary of the Invention

[0004] In view of the above-mentioned shortcomings in the prior art, the present invention provides an optimized design method for filter elements for aviation liquid-cooled electronic equipment, which solves the problems of low design efficiency and service life of filter elements for aviation liquid-cooled electronic equipment.

[0005] To achieve the above-mentioned objectives, the technical solution adopted by this invention is: an optimization design method for filter elements used in aviation liquid-cooled electronic equipment, comprising the following steps:

[0006] Step 1: Generate an initial population through chromosome structure. Each chromosome in the population consists of five parameters to be optimized: appropriate filter outer diameter, pleat wave number, pleat height, filter surface height, and filter surface thickness.

[0007] Step 2: For each chromosome in the current population, calculate the filter element fold angle based on its filter element outer diameter, fold wave number, and fold height;

[0008] Step 3: For each chromosome in the current population, calculate the filter cartridge filtration rate and total mass based on the filter cartridge pleat angle obtained from its filter cartridge height and thickness. Determine whether the filter cartridge filtration rate and total mass satisfy the filter cartridge filtration rate constraint and the filter cartridge total mass constraint. If the constraints are satisfied, proceed to step 4. If the constraints are not satisfied, reconstruct the current chromosome by changing the parameters to be optimized to satisfy the constraints, and return to step 2.

[0009] Step 4: For each chromosome in the current population, calculate the filter flow resistance according to Darcy's law based on its filter pleat angle, filter surface thickness, and filter pleat height. Determine whether the filter flow resistance meets the filter flow resistance constraint. If it meets the constraint, proceed to step 5. If it does not meet the constraint, reconstruct the current chromosome by changing the parameters to be optimized to meet the constraint, and return to step 2.

[0010] Step 5: For each chromosome in the current population, calculate the filter life function based on its filter pleat wavenumber, filter surface height, filter surface thickness, filter pleat height, and filter pleat angle.

[0011] Step 6: After the lifetime function of each chromosome in the current population has been calculated, determine whether the iteration termination condition has been met. If the iteration termination condition has not been met, generate the next generation population through selection, crossover, and mutation operations and return to Step 2. If the iteration termination condition has been met, select the chromosome with the highest lifetime function in the current population. The filter outer diameter, filter pleat wavenumber, filter pleat height, filter surface height, and filter surface thickness of this chromosome are the optimal configuration, thus completing the optimal design of the filter.

[0012] Further: The formula for calculating the filter element pleat angle in step 2 is as follows:

[0013]

[0014] In the above formula, θ is the filter element pleat angle, N is the filter element pleat wave number, D is the filter element outer diameter, and h is the filter element pleat height.

[0015] Furthermore: the formula for calculating the filter element filtration rate in step 3 is as follows:

[0016]

[0017] In the above formula, v d Q is the filter cartridge filtration rate. d H represents the coolant flow rate, and H represents the filter element's filtration surface height.

[0018] Further: The formula for calculating the total mass of the filter element in step 3 is:

[0019]

[0020] M f =ρ f ·π·H·L f ·(D-2·h-2·L)

[0021] In the above formula, M is the total mass of the filter element, M s For the filter element filtration surface quality, M f Let L be the mass of the metal support frame of the filter element, L be the thickness of the filter element's filtration surface, and ρ be the density of the filter element's filtration surface material. f The density of the metal support frame material for the filter element, L f This refers to the thickness of the metal support frame material.

[0022] Furthermore: the filter element filtration rate constraint and the filter element total mass constraint are as follows:

[0023] v d ≤v0

[0024] M≤M0

[0025] In the above formula, v0 is the maximum allowable filtration rate of the filter element, and M0 is the maximum allowable mass of the filter element.

[0026] Further: In step 4, the calculation of the filter element flow resistance based on Darcy's law specifically involves:

[0027] Step 41: Calculate the pressure loss caused by the filter surface;

[0028] Step 42: Calculate the pressure loss caused by the pleated structure;

[0029] Step 43: Add the pressure loss caused by the filter surface to the pressure loss caused by the pleated structure to obtain the filter element flow resistance ΔP.

[0030] Further: The formula for calculating the pressure loss caused by the filter surface in step 41 is as follows:

[0031]

[0032] In the above formula, ΔP m ρ is the pressure loss caused by the filter surface. l A is the fluid density of the coolant. h ξ is the area of ​​the filter screen pores, and ξ is the resistance coefficient.

[0033] The formula for calculating the drag coefficient ξ is as follows:

[0034]

[0035]

[0036] In the above formula, A is the filtration area of ​​the filter element, Re is the Reynolds number, η is the correction factor affected by the Reynolds number, μ is the kinematic viscosity of the coolant, and d f ν is the diameter of the filter element fiber, and v is the flow rate of the coolant.

[0037] Furthermore: the formula for calculating the pressure loss caused by the pleated structure in step 42 is as follows:

[0038] ΔP g =|ΔP g ′|·ρ l ·v 2

[0039] In the above formula, ΔP g ΔP represents the pressure loss caused by the folded structure. g ′ represents an intermediate variable used to calculate the pressure loss caused by the folded structure;

[0040] Among them, the intermediate variable ΔP g The formula for calculating ′ is:

[0041]

[0042] Furthermore: the filter element flow resistance constraint is:

[0043] ΔP≤ΔP0

[0044] In the above formula, ΔP0 is the maximum allowable flow resistance of the filter element.

[0045] Further: The filter life function in step 5 is:

[0046]

[0047] In the above formula, T is the filter element lifespan, N is the filter element pleat number, H is the filter element filtration surface height, L is the filter element filtration surface thickness, h is the filter element pleat height, and θ is the filter element pleat angle.

[0048] The beneficial effects of this invention are as follows: Given general constraints in filter element design such as filtration accuracy, system flow rate, filter element installation space, allowable filter element mass, and allowable flow resistance, this invention can directly provide the configuration of filter element structural parameters that maximize lifespan. This configuration includes five parameters that fully define the filter element structure: filter element outer diameter, filter element pleat number, filter element pleat height, filter element filter surface thickness, and filter element filter surface height. The method is simple and can be directly applied to engineering practice, overcoming the limitations of traditional case-by-case calculations. It has strong versatility and practicality, replacing the traditional "adjustment-simulation" design iteration steps, effectively improving filter element design efficiency and maintenance intervals, and increasing the economic benefits during filter element use. Attached Figure Description

[0049] Figure 1 A schematic cross-sectional view of a stainless steel metal fiber sintered felt filter element for aviation liquid-cooled electronic equipment.

[0050] Figure 2 This is a flowchart illustrating the optimal design method for filter elements used in aviation liquid-cooled electronic equipment according to the present invention.

[0051] Figure 3 This is a schematic diagram illustrating leakage caused by impurities in a blind-mating connector in the background art.

[0052] Among them, 1. Filter surface; 2. Metal support frame. Detailed Implementation

[0053] The specific embodiments of the present invention are described below to enable those skilled in the art to understand the present invention. However, it should be understood that the present invention is not limited to the scope of the specific embodiments. For those skilled in the art, various changes are obvious as long as they are within the spirit and scope of the present invention as defined and determined by the appended claims. All inventions utilizing the concept of the present invention are protected.

[0054] The filter element described in this invention is a stainless steel sintered felt filter element with adaptability to the temperature range, impact, vibration, flow resistance, flow rate, pressure resistance, corrosion resistance, and filtration accuracy requirements of avionics equipment platforms. Its structure is as follows: Figure 1 As shown, it consists of a pleated filter surface 1 and an internal metal support frame 2, which together form a hollow cylindrical structure.

[0055] like Figure 2 As shown, this invention proposes an optimal design method for filter elements used in aviation liquid-cooled electronic equipment. This method specifically includes the following steps:

[0056] Step 1: Generate an initial population through chromosome structure. Each chromosome in the population consists of five parameters to be optimized, including appropriate filter outer diameter, pleat wave number, pleat height, filter surface height, and filter surface thickness.

[0057] Step 2: For each chromosome in the current population, calculate the filter element fold angle based on its outer diameter, fold wave number, and fold height; where the filter element fold angle is:

[0058]

[0059] In the formula, θ is the filter element pleat angle. For ease of calculation, the filter element pleat angle described in this invention is half of the actual filter element pleat angle; N is the filter element pleat wave number; D is the filter element outer diameter; and h is the filter element pleat height.

[0060] Step 3: For each chromosome in the current population, calculate the filter cartridge filtration rate and total mass based on its filter cartridge height and thickness, using the calculated filter cartridge pleat angles. Determine if the filter cartridge filtration rate and total mass satisfy the filter cartridge filtration rate and total mass constraints. If they satisfy the constraints, proceed to Step 4. If they do not satisfy the constraints, reconstruct the current chromosome by changing the parameters to be optimized to satisfy the constraints, and return to Step 2. The filter cartridge filtration rate is:

[0061]

[0062] In the formula, v d Q is the filter cartridge filtration rate; d H represents the coolant flow rate; H represents the filter element's filtration surface height.

[0063] The filter rate constraint of the filter element is:

[0064] v d ≤v0 (3)

[0065] In the formula, v0 is the maximum allowable filtration rate of the filter element;

[0066] The total mass of the filter element consists of two parts: the mass of the filter element's filtration surface and the mass of the filter element's metal support frame. The mass of the filter element's filtration surface is:

[0067]

[0068] In the formula, M s ρ represents the mass of the filter element's filtration surface; L represents the thickness of the filter element's filtration surface; ρ represents the density of the filter element's filtration surface material.

[0069] The mass of the filter element metal support frame is:

[0070] M f =ρ f ·π·H·L f ·(D-2·h-2·L) (5)

[0071] In the formula, M f For the mass of the filter element's metal support frame; ρ f The density of the metal support frame material for the filter element; L f The thickness of the metal support frame material;

[0072] The total mass of the filter element is:

[0073] M = M s +M f (6)

[0074] In the formula, M is the total mass of the filter element.

[0075] The quality constraints for the filter element are:

[0076] M≤M0 (7)

[0077] In the formula, M0 is the maximum allowable mass of the filter element.

[0078] Step 4: For each chromosome in the current population, calculate the filter element flow resistance according to Darcy's law based on its filter element pleat angle, filter element surface thickness, and filter element pleat height. Determine if the filter element flow resistance meets the filter element flow resistance constraint. If it meets the constraint, proceed to Step 5; otherwise, reconstruct the current chromosome by changing the parameters to be optimized to meet the constraint, and return to Step 2. The filter element flow resistance consists of two parts: pressure loss caused by the filter surface and pressure loss caused by the pleat structure. The pressure loss caused by the filter surface is:

[0079]

[0080] In the formula, ΔP m The pressure loss caused by the filter surface; ρ l A is the fluid density of the coolant. h ξ is the area of ​​the filter screen pores; ξ is the resistance coefficient, which is calculated as follows:

[0081]

[0082] In the formula, A is the filtration area of ​​the filter element; Re is the Reynolds number; η is the correction factor affected by the Reynolds number; where the Reynolds number is calculated as:

[0083]

[0084] In the formula, μ is the kinematic viscosity of the coolant; d f The diameter of the filter element fibers;

[0085] The correction factors affected by the Reynolds number are obtained from Table 1:

[0086] Table 1

[0087]

[0088] The pressure loss caused by the pleated structure of the filter element is:

[0089] ΔP g =|ΔP g ′|·ρ l ·v 2 (11)

[0090] In the formula, ΔP g The pressure loss is caused by the pleated structure; v is the coolant flow rate; ΔP g ′ is an intermediate variable for calculating the pressure loss caused by the pleated structure, and its calculation is as follows;

[0091]

[0092] The flow resistance of the filter element is:

[0093] ΔP=ΔP m +ΔP g (13)

[0094] In the formula, ΔP is the filter element flow resistance;

[0095] The flow resistance constraint of the filter element is:

[0096] ΔP≤ΔP0 (14)

[0097] In the formula, ΔP0 is the maximum allowable flow resistance of the filter element.

[0098] Step 5: For each chromosome in the current population, calculate the filter life function based on its filter pleat wavenumber, filter surface height, filter surface thickness, filter pleat height, and filter pleat angle.

[0099] The filter life function is:

[0100]

[0101] In the formula, T is the characteristic value of filter life in this invention.

[0102] Step 6: After the lifetime function of each chromosome in the current population has been calculated, determine whether the iteration termination condition has been met. If the iteration termination condition has not been met, generate the next generation population through selection, crossover, and mutation operations and return to Step 2. If the iteration termination condition has been met, select the chromosome with the highest lifetime function in the current population. The filter outer diameter, filter pleat wavenumber, filter pleat height, filter surface height, and filter surface thickness of this chromosome are the optimal configuration, completing the optimal design of the filter. Among them, the iteration termination condition is the preset maximum number of generations; the selection operation uses the roulette wheel selection method to select chromosomes with high lifetime function values ​​to enter the next generation population with a higher probability; the crossover operation selects a split point in the selected parent chromosomes and exchanges the chromosomes before or after the split point to form two new offspring chromosomes; the mutation operation randomly selects a parameter to be optimized in the chromosome and randomly changes it to another new value to form a new offspring chromosome.

[0103] The optimal design method for filter elements used in aviation liquid-cooled electronic equipment, as presented in this invention, establishes a system model for selecting the optimal structural design parameters for filter elements. Given general constraints on filter element design such as filtration accuracy, system flow rate, filter element installation space, allowable filter element mass, and allowable flow resistance, the method can directly provide the filter element structural parameter configuration with the highest lifespan. Based on the filtration requirements and installation limitations of aviation liquid-cooled electronic equipment, this invention selects appropriate filter element outer diameter, pleat number, pleat height, filter surface thickness, and filter surface height to ensure that filtration rate, mass, and flow resistance meet the requirements. Simultaneously, the product of the filter area and the filter surface thickness is used as a characterization value for filter element lifespan, and a filter element lifespan function is calculated. Finally, through genetic mutation iteration, the optimal configuration with the highest lifespan is obtained. This method is of great significance for improving filter element design efficiency, filter element maintenance intervals, and enhancing the economic benefits during filter element use.

Claims

1. An optimal design method for filter elements used in aviation liquid-cooled electronic equipment, characterized in that, Includes the following steps: Step 1: Generate an initial population through chromosome structure. Each chromosome in the initial population consists of five parameters to be optimized: appropriate filter outer diameter, pleat wave number, pleat height, filter surface height, and filter surface thickness. Step 2: For each chromosome in the current population, calculate the filter element fold angle based on its filter element outer diameter, fold wave number, and fold height; Step 3: For each chromosome in the current population, calculate the filter cartridge filtration rate and total mass based on the filter cartridge pleat angle obtained from its filter cartridge height and thickness. Determine whether the filter cartridge filtration rate and total mass satisfy the filter cartridge filtration rate constraint and the filter cartridge total mass constraint. If the constraints are satisfied, proceed to step 4. If the constraints are not satisfied, reconstruct the current chromosome by changing the parameters to be optimized to satisfy the constraints, and return to step 2. Step 4: For each chromosome in the current population, calculate the filter flow resistance according to Darcy's law based on its filter pleat angle, filter surface thickness, and filter pleat height. Determine whether the filter flow resistance meets the filter flow resistance constraint. If it meets the constraint, proceed to step 5. If it does not meet the constraint, reconstruct the current chromosome by changing the parameters to be optimized to meet the constraint, and return to step 2. Step 5: For each chromosome in the current population, calculate the filter life function based on its filter pleat wave number, filter surface height, filter surface thickness, filter pleat height, and filter pleat angle. Step 6: After the lifetime function of each chromosome in the current population has been calculated, determine whether the iteration termination condition has been met. If the iteration termination condition has not been met, generate the next generation population through selection, crossover, and mutation operations and return to Step 2. If the iteration termination condition has been met, select the chromosome with the highest lifetime function in the current population. The filter outer diameter, filter pleat wavenumber, filter pleat height, filter surface height, and filter surface thickness of this chromosome are the optimal configuration, thus completing the optimal design of the filter.

2. The optimal design method for filter elements of aviation liquid-cooled electronic equipment according to claim 1, characterized in that, The formula for calculating the filter element pleat angle in step 2 is as follows: In the above formula, θ is the filter element pleat angle, N is the filter element pleat wave number, D is the filter element outer diameter, and h is the filter element pleat height.

3. The optimal design method for filter elements of aviation liquid-cooled electronic equipment according to claim 2, characterized in that, The formula for calculating the filter element filtration rate in step 3 is as follows: In the above formula, v d Q is the filter cartridge filtration rate. d H represents the coolant flow rate, and H represents the filter element's filtration surface height.

4. The optimal design method for filter elements of aviation liquid-cooled electronic equipment according to claim 3, characterized in that, The formula for calculating the total mass of the filter element in step 3 is as follows: M=M s +M f M f =ρ f ·p·H·L f ·(D-2·h-2·L) In the above formula, M is the total mass of the filter element, M s For the filter element filtration surface quality, M f Let L be the mass of the metal support frame of the filter element, L be the thickness of the filter element's filtration surface, and ρ be the density of the filter element's filtration surface material. f The density of the metal support frame material for the filter element, L f This refers to the thickness of the metal support frame material.

5. The optimal design method for filter elements of aviation liquid-cooled electronic equipment according to claim 4, characterized in that, The filter element filtration rate constraint and the filter element total mass constraint are as follows: in d ≤v0 M≤M0 In the above formula, v0 is the maximum allowable filtration rate of the filter element, and M0 is the maximum allowable mass of the filter element.

6. The optimal design method for filter elements of aviation liquid-cooled electronic equipment according to claim 5, characterized in that, In step 4, the calculation of the filter element flow resistance based on Darcy's law is specifically as follows: Step 41: Calculate the pressure loss caused by the filter surface; Step 42: Calculate the pressure loss caused by the pleated structure; Step 43: Add the pressure loss caused by the filter surface to the pressure loss caused by the pleated structure to obtain the filter element flow resistance ΔP.

7. The optimal design method for filter elements of aviation liquid-cooled electronic equipment according to claim 6, characterized in that, The formula for calculating the pressure loss caused by the filter surface in step 41 is as follows: In the above formula, ΔP m ρ is the pressure loss caused by the filter surface. l A is the fluid density of the coolant. h ξ is the area of ​​the filter screen pores, and ξ is the resistance coefficient. The formula for calculating the drag coefficient ξ is as follows: In the above formula, A is the filtration area of ​​the filter element, Re is the Reynolds number, η is the correction factor affected by the Reynolds number, μ is the kinematic viscosity of the coolant, and d f ν is the diameter of the filter element fiber, and v is the flow rate of the coolant.

8. The optimal design method for filter elements of aviation liquid-cooled electronic equipment according to claim 7, characterized in that, The formula for calculating the pressure loss caused by the folded structure in step 42 is as follows: ΔP g =|ΔP g ′|ρ l ·v 2 In the above formula, ΔP g ΔP represents the pressure loss caused by the folded structure. g ′ represents an intermediate variable used to calculate the pressure loss caused by the folded structure; Among them, the intermediate variable ΔP g The formula for calculating ′ is:

9. The optimal design method for filter elements of aviation liquid-cooled electronic equipment according to claim 6, characterized in that, The filter element flow resistance constraint is: ΔP≤ΔP0 In the above formula, ΔP0 is the maximum allowable flow resistance of the filter element.

10. The optimal design method for filter elements of aviation liquid-cooled electronic equipment according to claim 1, characterized in that, The filter cartridge life function is: In the above formula, T is the filter element lifespan, N is the filter element pleat number, H is the filter element filtration surface height, L is the filter element filtration surface thickness, h is the filter element pleat height, and θ is the filter element pleat angle.

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