Simple design method of low-cost embedded core module radiator

Abstract

The invention relates to a low-cost simple design method for an embedded core module radiator, and the method comprises the steps: firstly constructing a radiator design model which is composed of a substrate, a plurality of tooth sheets, air channels formed between the tooth sheets, and a radiating step below the substrate; then, the power consumption of the radiator is preset, the height of a tooth piece is estimated, natural heat dissipation and forced air cooling heat dissipation are evaluated according to a natural heat dissipation and forced air cooling heat dissipation evaluation algorithm, and if the evaluation result is forced air cooling heat dissipation, the power consumption of the radiator is estimated based on an air channel characteristic curve of the radiator and a characteristic curve of a cooling fan. Calculating a radiator height suggestion value according to a forced air cooling radiator design algorithm; compared with a common experimental method and a computer simulation design method, the technical scheme has the advantages that the scheme is simple and convenient, the design success rate based on the embedded core module of the company is high, and repeated revision or rework processing is avoided.

Description

Technical Field

[0001] The invention relates to the technical field of embedded core module radiator design, and in particular to a simple design method for a low-cost embedded core module radiator. Background Art

[0002] At present, radiator design mainly relies on two methods: experimental method and computer simulation design for design verification. However, these two methods each have some problems and challenges. The experimental method is a traditional radiator design method, which relies on the designer's actual operation and design experience, and its success rate is often low; with the rapid development of computer technology, computer thermal simulation design method has gradually become an important means in the field of radiator design. However, the computer thermal simulation design method has problems such as high requirements on engineers' thermal design theory and practical experience, and high requirements on computer configuration for simulation. Therefore, what kind of radiator design method should be adopted to achieve a simple and convenient radiator design scheme, a high design success rate, and avoid multiple revisions or rework, which is a technical problem faced by technical personnel in this field. Summary of the invention

[0003] To achieve the above object, the present invention provides the following technical solution: a simple design method for a low-cost embedded core module heat sink, the simple design method comprising the following steps:

[0004] Step 1: construct a heat sink design model, which consists of a base plate, multiple teeth, air ducts formed between the teeth, and a heat dissipation step under the base plate, wherein the base plate length and base plate width are determined by the length and width of the embedded core module, the base plate thickness is set to H1, the tooth thickness is set to H2, and the air duct width is set to W1.

[0005] Step 2: Evaluate the natural cooling and forced air cooling according to the “natural cooling and forced air cooling evaluation” algorithm, wherein the “natural cooling and forced air cooling evaluation” algorithm includes:

[0006] The power consumption of the radiator is preset, and the height of the tooth plate is estimated. Then, according to the existing conditions of the radiator of the radiator model, the effective surface area of ​​the tooth plate is calculated. Then, the heat flux density of the radiator is calculated by the ratio of the preset power consumption of the radiator to the effective surface area of ​​the tooth plate. Finally, the calculated value of the heat flux density is compared with the threshold value of the heat flux density. If the calculated value of the heat flux density is not less than the threshold value, forced air cooling is adopted and step 3 is executed. If the calculated value of the heat flux density is less than the threshold value, natural cooling is adopted.

[0007] Step 3: Obtain the recommended value of the radiator height according to the "forced air cooling radiator design" algorithm; the "forced air cooling radiator design" algorithm is based on the duct characteristic curve of the radiator and the characteristic curve of the cooling fan, including: taking the radiator air volume requirement and wind resistance requirement as the coordinates of the intersection of the duct characteristic curve of the radiator and the characteristic curve of the cooling fan, and as the coordinates of the optimal working point, and then constructing an equation based on the intersection of the curves, with the radiator height as a variable, and the existing conditions of the cooling fan and the radiator as constants, and obtaining the recommended value of the radiator height by solving the equation.

[0008] Preferably, the substrate thickness H1 is set to 1.5 mm, the tooth thickness H2 is set to 0.8 mm, and the air duct width W1 is set to 2.5 mm.

[0009] Preferably, the threshold value of the heat flux density is 0.04 W / cm2.

[0010] Preferably, the method for calculating the effective surface area of ​​the radiator comprises the following sub-steps:

[0011] Sub-step 21: Estimate the number of air ducts. The calculation method is as follows:

[0012] Number of air ducts = substrate width / (air duct width+tooth plate thickness), where the number of air ducts must be an integer. If the calculated number of air ducts is not an integer, it will be rounded down;

[0013] Sub-step 22: Calculate the effective surface area of ​​the tooth segment as follows:

[0014] The effective surface area of ​​the tooth part = [2*(estimated tooth height*tooth thickness)+2*(estimated tooth height*base length)+tooth thickness*tooth length]*(number of air ducts+1)+

[0015] Duct width*substrate length*number of ducts

[0016] Sub-step 23: Ignore the effect of the heat dissipation step on the surface area of ​​the heat sink and calculate the effective surface area of ​​the substrate. The calculation method is as follows:

[0017] Substrate effective surface = 2*(substrate width*substrate thickness)+2*(substrate length*substrate thickness)+substrate length*substrate width;

[0018] Sub-step 24: Calculate the effective surface area of ​​the heat sink as follows:

[0019] Radiator effective surface area = effective surface area of ​​the tooth plate part + effective surface area of ​​the base plate. Preferably, the "forced air cooling radiator design" algorithm includes the following sub-steps:

[0020] Sub-step 31: Obtaining the system maximum power consumption, maximum shell temperature, and working environment temperature requirement values ​​of the radiator;

[0021] Sub-step 32: Formula 1, according to the heat balance equation, calculate the radiator air volume requirement, formula 1 is as follows:

[0022] L=Q / (ρCpΔt)

[0023] Where Q is the maximum power consumption of the heat sink system, which is a known quantity in kW, Δt is the difference between the maximum shell temperature of the heat sink and the working environment temperature, which is a calculated known quantity in °C, ρ is the air density of 1.1kg / m3, Cp is the specific heat of air of 1.005kJ / (kg·℃), and L is the actual air volume requirement of the heat sink, which is a process quantity in m3 / min;

[0024] Sub-step 33: Formula 2, based on the air volume and wind resistance data provided by the fan, construct the fan's air volume-wind resistance function as follows:

[0025] R=-WpL+Cq

[0026] Wherein, L is the radiator air volume requirement obtained in Formula 1, which is the process quantity calculated by Formula 1; Wp is the minimum air volume of the selected cooling fan, which is a known quantity provided by the cooling fan specification number, and its unit is m3 / min; Cq is the minimum wind resistance of the selected cooling fan, which is a known quantity provided by the cooling fan specification number, and its unit is Pa; R is the radiator wind resistance requirement obtained by the radiator air volume demand data at the intersection of the radiator's air duct characteristic curve and the cooling fan's characteristic curve, which is a process quantity, and its unit is Pa.

[0027] Sub-step 34: Formula 3, calculate the equivalent hydraulic radius of the radiator duct as follows:

[0028]

[0029] Where: a, b are the width and height of the heat sink air duct respectively. Figure 2 As shown, a is the radiator duct width (corresponding to W1), which is a known quantity, and b is the radiator fin height (corresponding to H3), which is an unknown quantity to be determined.

[0030] Sub-step 35: Formula 4 calculates the average velocity of the air in the air duct as follows:

[0031] v=L / (60cab)

[0032] Where c is the number of air ducts, which is the process quantity obtained by the method of "Sub-step 21" in the above-mentioned "Natural Cooling and Forced Air Cooling Cooling Evaluation" algorithm. The constant 60 is used for unit conversion, so that the final average flow rate unit is converted from m3 / s to m3 / min, which is convenient for converting the data into a unit consistent with the cooling fan air volume unit m3 / min. a is the radiator duct width, which is a known quantity, and b is the radiator fin height, which is an unknown quantity to be calculated.

[0033] Sub-step 36: Formula 5, construct an equation with the cooling fan and radiator as known quantities and the radiator height as an unknown quantity, as follows:

[0034]

[0035] Where λ is the friction coefficient, which is about 0.022, is the air density, y is the length of the heat sink, which is a known quantity, Rs is the equivalent hydraulic radius of the radiator duct, which is a process quantity including the unknown quantity of the radiator fin height, and is obtained by Formula 3, R is the process quantity calculated by Formula 2, v is the average flow rate of the air in the duct, which is a process quantity including the unknown quantity of the radiator fin height, and is obtained by Formula 4.

[0036] Sub-step 37: Integrate Formula 1, Formula 2, Formula 3, Formula 4, and Formula 5, and solve the equation constructed by Formula 5 to obtain the recommended value of the unknown quantity, the heat sink fin height. Finally, add the heat sink fin height, the heat sink base thickness, and the heat sink step thickness to obtain the recommended value of the heat sink height.

[0037] The present invention has the following beneficial effects:

[0038] This simple design method can be highly customized for the size, power consumption and working environment of specific embedded core modules. Through algorithm evaluation and design optimization, it can significantly reduce the number of design iterations, have a high design success rate, avoid multiple revisions or rework, and accordingly speed up the product launch.

[0039] This simple design method is presented in clear and concise steps, so that even inexperienced engineers can quickly get started and design an effective heat sink, which helps to lower the design threshold and promote the popularization and application of heat dissipation technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 is a flow chart of the present invention;

[0041] Figure 2 A design model diagram of the radiator provided by the present invention;

[0042] Figure 3The radiator's air duct characteristic curve and the cooling fan's characteristic curve; DETAILED DESCRIPTION

[0043] The technical solution in one embodiment of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0044] See also Figure 1-3 :

[0045] Construct a heat sink design model, which consists of a base plate, multiple teeth, air ducts formed between the teeth, and a heat dissipation step under the base plate. The base plate length and width are determined by the length and width of the embedded core module. The base plate thickness is set to 1.5mm, the tooth thickness is set to 0.8mm, and the air duct width is set to 2.5mm. These three dimensions are the optimal solutions obtained after multiple experimental iterations. The design model based on these three dimensions is combined with the "natural heat dissipation and forced air cooling heat dissipation evaluation" algorithm or the "forced air cooling heat sink design" algorithm to shorten the embedded core module heat sink design cycle, improve the heat sink design quality, and bring benefits to the development of embedded core module heat sink related work.

[0046] 1. Requirement 1: The maximum power consumption of an embedded core module is 10W, the length and width are 60.5*41.5mm, and the estimated fin height of the radiator is 15mm. The calculation process is as follows:

[0047] 1) Based on the radiator design model, the "natural heat dissipation and forced air cooling heat dissipation evaluation" algorithm is used to evaluate whether the radiator needs to be designed with a fan. The calculation process is as follows:

[0048] 1) Estimate the number of air ducts. The calculation process is as follows:

[0049] Number of air ducts = baseboard width / (air duct width + tooth thickness)

[0050] =41.5÷(2.5+0.8)=12

[0051] 2) Calculate the effective surface area of ​​the tooth segment. The calculation process is as follows:

[0052] The effective surface area of ​​the tooth part = [2*(estimated tooth height*tooth thickness)+2*(estimated tooth height*base length)+tooth thickness*tooth length]*(number of air ducts+1)+air duct width*base length*number of air ducts

[0053] =[2*(15*0.8)+2*(15*60.5)+0.8*60.5]*(12+1)+2.5*60.5*12

[0054] =26351.2mm 2

[0055] 3) Ignore the effect of the heat dissipation step on the surface area of ​​the radiator and calculate the effective surface area of ​​the substrate. The calculation process is as follows:

[0056] Substrate effective surface = 2*(substrate width*substrate thickness)+2*(substrate length*substrate thickness)+substrate length*substrate width

[0057] =2*(41.5*1.5)+2*(60.5*1.5)+60.5*41.5

[0058] =2816.75mm 2

[0059] 4) Add the effective surface area of ​​the tooth part and the effective surface area of ​​the base plate calculated in 2) and 3) above to obtain the effective surface area of ​​the radiator. The calculation process is as follows:

[0060] Radiator effective surface area = effective surface area of ​​the tooth plate + effective surface area of ​​the base plate

[0061] =26351.2+2816.75=29167.95mm 2 =291.6795cm 2

[0062] 5) Calculate the heat flux density of the radiator. The calculation process is as follows:

[0063] Heat flux density of heat sink = estimated power consumption of embedded core module / effective surface area of ​​heat sink

[0064] =10÷291.6795=0.034W / cm 2

[0065] 6) Because the calculated heat flux density is less than 0.04W / cm2, according to the standard judgment provided by the "Natural Cooling and Forced Air Cooling Heat Dissipation Evaluation" algorithm, it is concluded that when the radiator fin height is 15mm, the "natural cooling" (fanless design) heat dissipation method can be selected for heat dissipation design.

[0066] 7) Take the fin height of the radiator as 15mm, and add the radiator base thickness (known quantity) and the radiator heat dissipation step thickness (known quantity) to obtain the recommended radiator design height. The calculation process is as follows:

[0067] Recommended radiator design height = radiator fin height + radiator base thickness + radiator cooling step thickness

[0068] =15+1.5+2=18.5mm

[0069] 2. Requirement 2: The maximum power consumption of an embedded core module is 10W, the length and width are 60.5*41.5mm (consistent with requirement 1), the estimated fin height of the radiator is 10mm, and the heat dissipation step thickness is 2mm. The calculation process is as follows:

[0070] 1) Estimate the number of air ducts, which is 12 based on requirement 1:

[0071] 2) Calculate the effective surface area of ​​the tooth segment. The calculation process is as follows:

[0072] The effective surface area of ​​the tooth part = [2*(estimated tooth height*tooth thickness)+2*(estimated tooth height*base length)+tooth thickness*tooth length]*(number of air ducts+1)+air duct width*base length*number of air ducts

[0073] =[2*(10*0.8)+2*(10*60.5)+0.8*60.5]*(12+1)+2.5*60.5*12

[0074] =18382.2mm 2

[0075] 3) Ignore the effect of the heat dissipation step on the surface area of ​​the radiator and calculate the effective surface area of ​​the substrate. Based on requirement 1, it is 2816.75mm 2

[0076] 4) Add the effective surface area of ​​the tooth part and the effective surface area of ​​the base plate calculated in 2) and 3) above to obtain the effective surface area of ​​the radiator. The calculation process is as follows:

[0077] Radiator effective surface area = effective surface area of ​​the tooth plate + effective surface area of ​​the base plate

[0078] =18382.2+2816.75=21198.95mm 2 =211.9895cm 2

[0079] 5) Calculate the heat flux density of the radiator. The calculation process is as follows:

[0080] Heat flux density of heat sink = estimated power consumption of embedded core module / effective surface area of ​​heat sink

[0081] =10÷211.9895=0.047W / cm 2

[0082] 6) Because the calculated heat flux density is greater than 0.04W / cm2, according to the standard judgment provided by the "Natural Heat Dissipation and Forced Air Cooling Heat Dissipation Evaluation" algorithm, it is concluded that when the radiator fin height is 10mm, the "Forced Air Cooling" (with fan design) heat dissipation method must be used for heat dissipation design.

[0083] 7) According to the algorithm requirements of "forced air-cooled radiator design", further improve requirement 2, obtain the ambient temperature Q is 85℃, the maximum shell temperature of the heat dissipation device is 110℃, the minimum wind pressure of the fan is 5.34mm-H2O (approximately equal to 52.46Pa), and the minimum air volume is 0.13m3 / min.

[0084] 8) Calculate the radiator air volume requirement. The calculation process is as follows:

[0085] L=Q / (ρCpΔt)=(10 / 1000) / (1.1*1.005*(110-85))=0.000362m 3 / min

[0086] 9) The wind resistance at the intersection (optimal working point) of the estimated duct characteristic curve of the radiator and the characteristic curve of the cooling fan is calculated through the fan air volume-wind resistance function as follows:

[0087] R=-WpL+Cq=-0.13*0.000362+52.46=52.46Pa

[0088] 10) The calculation process of the equivalent hydraulic radius of the radiator duct is as follows, where b is the unknown quantity to be calculated:

[0089] Rs=ab / [2(a+b)]=10*b / [2*(10 / 100+b)]=5b / (0.1+b)

[0090] 11) The calculation process of the average air velocity in the radiator duct is as follows, where b is the unknown quantity to be calculated:

[0091] v=L / (60cab)=0.000362 / (60*(10 / 100)*b)=0.000362 / 6b

[0092] 12) Combine the process quantities of 10) and 11) to construct an equation with the cooling fan and radiator as known quantities and the radiator height as an unknown quantity. The calculation process is as follows:

[0093]

[0094] ->[0.022*(0.000362 / 6b)2*1.18*(60.5 / 100)] / {4*[5b / (0.1+b)]*2}=52.46

[0095] Solving the above equation, we get b is approximately equal to 12.2 mm

[0096] 13) Based on requirement 2 and the above calculation process, the minimum height of the radiator fins is 12.2 mm, which means that the estimated radiator fin height of 10 mm cannot be met, and the radiator fin height should be designed to be greater than 12.2 mm.

[0097] 14) Take the fin height of the heat sink as 12.2mm, and add the radiator base thickness (known quantity) and the radiator heat dissipation step thickness (known quantity) to obtain the recommended value of the radiator design height. The calculation process is as follows:

[0098] Recommended radiator design height = radiator fin height + radiator base thickness + radiator cooling step thickness

[0099] =12.2+1.5+2=15.7mm.

[0100] The above are only embodiments of the present invention, and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A simple design method for a low-cost embedded core module heat sink, characterized by: The simple design method comprises the following steps: Step 1: construct a heat sink design model, which consists of a base plate, multiple teeth, air ducts formed between the teeth, and a heat dissipation step under the base plate, wherein the base plate length and base plate width are determined by the length and width of the embedded core module, the base plate thickness is set to H1, the tooth thickness is set to H2, and the air duct width is set to W1. Step 2: Evaluate the natural cooling and forced air cooling according to the "natural cooling and forced air cooling heat dissipation evaluation" algorithm, wherein the "natural cooling and forced air cooling heat dissipation evaluation" algorithm includes: The power consumption of the radiator is preset, and the height of the tooth plate is estimated. Then, according to the existing conditions of the radiator of the radiator model, the effective surface area of ​​the tooth plate is calculated. Then, the heat flux density of the radiator is calculated by the ratio of the preset power consumption of the radiator to the effective surface area of ​​the tooth plate. Finally, the calculated value of the heat flux density is compared with the threshold value of the heat flux density. If the calculated value of the heat flux density is not less than the threshold value, forced air cooling is adopted and step 3 is executed. If the calculated value of the heat flux density is less than the threshold value, natural cooling is adopted. Step 3: Obtain the recommended value of the radiator height according to the "forced air cooling radiator design" algorithm; the "forced air cooling radiator design" algorithm is based on the duct characteristic curve of the radiator and the characteristic curve of the cooling fan, including: taking the radiator air volume requirement and wind resistance requirement as the coordinates of the intersection of the duct characteristic curve of the radiator and the characteristic curve of the cooling fan, and as the coordinates of the optimal working point, and then constructing an equation based on the intersection of the curves, with the radiator height as a variable, and the existing conditions of the cooling fan and the radiator as constants, and obtaining the recommended value of the radiator height by solving the equation.

2. A simple design method for a low-cost embedded core module heat sink according to claim 1, characterized in that: The substrate thickness H1 is set to 1.5 mm, the tooth thickness H2 is set to 0.8 mm, and the air duct width W1 is set to 2.5 mm.

3. A simple design method for a low-cost embedded core module heat sink according to claim 1, characterized in that: The threshold value of the heat flux density is 0.04 W / cm2.

4. A simple design method for a low-cost embedded core module heat sink according to claim 1, characterized in that: The method for calculating the effective surface area of ​​the radiator comprises the following sub-steps: Sub-step 21: Estimate the number of air ducts. The calculation method is as follows: Number of air ducts = substrate width / (air duct width+tooth plate thickness), where the number of air ducts must be an integer. If the calculated number of air ducts is not an integer, it will be rounded down; Sub-step 22: Calculate the effective surface area of ​​the tooth segment as follows: The effective surface area of ​​the tooth part = [2*(estimated tooth height*tooth thickness)+2*(estimated tooth height*base length)+tooth thickness*tooth length]*(number of air ducts+1)+air duct width*base length*number of air ducts Sub-step 23: Ignore the effect of the heat dissipation step on the surface area of ​​the heat sink and calculate the effective surface area of ​​the substrate. The calculation method is as follows: Substrate effective surface = 2*(substrate width*substrate thickness)+2*(substrate length*substrate thickness)+substrate length*substrate width; Sub-step 24: Calculate the effective surface area of ​​the heat sink as follows: The effective surface area of ​​the radiator = the effective surface area of ​​the tooth plate part + the effective surface area of ​​the base plate.

5. A simple design method for a low-cost embedded core module heat sink according to claim 4, characterized in that: The "forced air cooling radiator design" algorithm includes the following sub-steps: Sub-step 31: Obtaining the system maximum power consumption, maximum shell temperature, and working environment temperature requirement values ​​of the radiator; Sub-step 32: Formula 1, according to the heat balance equation, calculate the radiator air volume requirement, formula 1 is as follows: L=Q / (ρCpΔt) Where Q is the maximum power consumption of the heat sink system, which is a known quantity in kW, Δt is the difference between the maximum shell temperature of the heat sink and the working environment temperature, which is a calculated known quantity in °C, ρ is the air density of 1.1kg / m3, Cp is the specific heat of air of 1.005kJ / (kg·℃), and L is the actual air volume requirement of the heat sink, which is a process quantity in m3 / min; Sub-step 33: Formula 2, based on the air volume and wind resistance data provided by the fan, construct the fan's air volume-wind resistance function as follows: R=-WpL+Cq Wherein, L is the radiator air volume requirement obtained in Formula 1, which is the process quantity calculated by Formula 1; Wp is the minimum air volume of the selected cooling fan, which is a known quantity provided by the cooling fan specification number, and its unit is m3 / min; Cq is the minimum wind resistance of the selected cooling fan, which is a known quantity provided by the cooling fan specification number, and its unit is Pa; R is the radiator wind resistance requirement obtained by the radiator air volume demand data at the intersection of the radiator's air duct characteristic curve and the cooling fan's characteristic curve, which is a process quantity, and its unit is Pa. Sub-step 34: Formula 3, calculate the equivalent hydraulic radius of the radiator duct as follows: In the formula: a and b are the width and height of the heat sink air duct respectively, where a is the width of the radiator air duct, which is a known quantity, and b is the height of the radiator fin, which is an unknown quantity to be determined. Sub-step 35: Formula 4 calculates the average velocity of the air in the air duct as follows: v=L / (60cab) Where c is the number of air ducts, which is the process quantity obtained by the method of "Sub-step 21" in the above "Natural Cooling and Forced Air Cooling Cooling Evaluation" algorithm. The constant 60 is used for unit conversion, so that the final average flow rate unit is converted from m3 / s to m3 / min, which is convenient for converting the data into a unit consistent with the cooling fan air volume unit m3 / min. a is the radiator duct width, which is a known quantity, and b is the radiator fin height, which is an unknown quantity to be calculated. Sub-step 36: Formula 5, construct an equation with the cooling fan and radiator as known quantities and the radiator height as an unknown quantity, as follows: Where λ is the friction coefficient, which is about 0.022, is the air density, y is the length of the heat sink, which is a known quantity, Rs is the equivalent hydraulic radius of the radiator duct, which is a process quantity including the unknown quantity of the radiator fin height, and is obtained by Formula 3, R is the process quantity calculated by Formula 2, v is the average flow rate of the air in the duct, which is a process quantity including the unknown quantity of the radiator fin height, and is obtained by Formula 4. Sub-step 37: Integrate Formula 1, Formula 2, Formula 3, Formula 4, and Formula 5, and solve the equation constructed by Formula 5 to obtain the recommended value of the unknown quantity, the heat sink fin height. Finally, add the heat sink fin height, the heat sink base thickness, and the heat sink step thickness to obtain the recommended value of the heat sink height.

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