A simple design method of low-cost embedded core module heat sink

Abstract

The application relates to a simple design method of a low-cost embedded core module radiator, which comprises the following steps: firstly, a radiator design model is constructed, the radiator design model is composed of a substrate, a plurality of radiator fins, air ducts formed between the radiator fins, and a heat dissipation step below the substrate; secondly, the radiator power consumption is preset, the radiator fin height 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, if the evaluation result is forced air cooling heat dissipation, then the radiator height suggestion value is obtained based on the air duct characteristic curve of the radiator and the characteristic curve of a heat dissipation fan and according to a forced air cooling radiator design algorithm; compared with general experimental methods and computer simulation design methods, the technical scheme has the advantages of simple and convenient scheme, high design success rate based on the embedded core module of the company, and the like.

Description

Technical Field

[0001] The present 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 that 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, is a technical problem faced by those skilled in the art. 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 heat sink fins, air ducts formed between the heat sink fins, and a heat dissipation step below 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 H1, the heat sink fin thickness is set to H2, and the heat sink 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 heat dissipation evaluation” algorithm, wherein the “natural cooling and forced air cooling heat dissipation evaluation” algorithm includes:

[0006] The radiator power consumption is preset, and the radiator fin height is estimated. Then, based on the existing conditions of the radiator in the radiator model, the effective surface area of ​​the radiator fins is calculated. The heat flux density of the radiator is then calculated by the ratio of the preset radiator power consumption to the effective surface area of ​​the radiator fins. Finally, the calculated heat flux density is compared with the heat flux density threshold. If the calculated heat flux density is not less than the threshold, forced air cooling is used and step 3 is executed. If the calculated heat flux density is less than the threshold, natural cooling is used.

[0007] Step 3: Obtain the recommended radiator height value according to the "forced air cooling radiator design" algorithm; the "forced air cooling radiator design" algorithm is based on the radiator's air duct characteristic curve and the cooling fan's characteristic curve, including: constructing the fan's air volume-wind resistance function based on the radiator's air volume demand and wind resistance demand, and obtaining the radiator's wind resistance demand at the intersection of the radiator's air duct characteristic curve and the cooling fan's characteristic curve based on the radiator's air volume demand data. Then, construct an equation based on the intersection of the curves, with the radiator's fin height as a variable and the existing conditions of the cooling fan and radiator as constants. After solving the equation, the recommended radiator fin height value is obtained. The radiator fin height is added to the radiator base plate thickness and the radiator heat dissipation step thickness to obtain the recommended radiator height.

[0008] Preferably, the substrate thickness H1 is set to 1.5 mm, the heat sink fin 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 includes the following sub-steps:

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

[0012] Number of ducts = baseboard width / (duct width + radiator fin thickness), where the number of ducts must be an integer. If the calculated number of ducts is not an integer, it will be rounded down.

[0013] Sub-step 22: Calculate the effective surface area of ​​the fins of the radiator using the following method:

[0014] The effective surface area of ​​the radiator fins = [2*(estimated radiator fin height*radiator fin thickness) + 2*(estimated radiator fin height*base plate length) + radiator fin thickness*radiator fin length]*(number of ducts+1) + duct width*base plate length*number of ducts

[0015] Sub-step 23: Ignore the effect of the heat dissipation step on the heat sink surface area and calculate the effective surface area of ​​the base plate. The calculation method is as follows:

[0016] Substrate effective surface area = 2*(substrate width*substrate thickness)+2*(substrate length*substrate thickness)+substrate length*substrate width;

[0017] Sub-step 24: Calculate the effective surface area of ​​the radiator as follows:

[0018] The effective surface area of ​​the radiator = the effective surface area of ​​the fins of the radiator + the effective surface area of ​​the base plate.

[0019] 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 required working environment temperature of the radiator;

[0021] Sub-step 32: Formula 1, based on the heat balance equation, calculate the radiator air volume requirement. Formula 1 is as follows: Where Q is the maximum system power consumption of the heat sink, which is a known quantity in kW, Δt is the difference between the maximum case temperature of the heat sink and the operating ambient temperature, which is a calculated known quantity in °C, ρ is the air density of 1.1 kg / m³, Cp is the specific heat of air of 1.005 kJ / (kg·°C), and L is the actual air volume required by the heat sink, which is a process quantity in m³ / min.

[0022] 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:

[0023] R=-WpL+Cq

[0024] Where L is the radiator air volume demand 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 specifications, and the 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 specifications, and the unit is Pa; R is the radiator wind resistance demand obtained from the radiator air volume demand data at the intersection of the radiator's air duct characteristic curve and the cooling fan characteristic curve, which is a process quantity, and the unit is Pa.

[0025] Sub-step 34: Formula 3, calculate the equivalent hydraulic radius of the radiator duct as follows: Where: W1 is the width of the air duct, b is the height of the radiator fins, and is the unknown quantity to be determined;

[0026] Sub-step 35: Formula 4 calculates the average flow rate of air in the duct as follows: 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 to convert the final average flow rate unit from m3 / s to m3 / min, which facilitates the conversion of this data into units consistent with the cooling fan air volume unit m3 / min. W1 is the air duct width, which is a known quantity. b is the radiator fin height, which is an unknown quantity to be determined.

[0027] Sub-step 36: Formula 5, construct the equation with the cooling fan and radiator as known quantities and the radiator height as an unknown quantity, as follows: in is the friction coefficient, which is 0.022, is the air density, y is the fin length, 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, and 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.

[0028] 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 radiator fin height. Finally, add the radiator fin height, the radiator base plate thickness, and the radiator heat dissipation step thickness to obtain the recommended radiator height.

[0029] The present invention has the following beneficial effects:

[0030] 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, increase the design success rate, avoid multiple revisions or rework, and accordingly accelerate the time to market.

[0031] This simple design method is presented in clear and concise steps, allowing even inexperienced engineers to quickly get started and design an effective heat sink. This helps lower the design threshold and promotes the popularization and application of heat dissipation technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 is a flow chart of the present invention;

[0033] Figure 2 The radiator design model diagram provided by the present invention;

[0034] Figure 3 The radiator's air duct characteristic curve and the cooling fan's characteristic curve; DETAILED DESCRIPTION

[0035] The technical solution in one embodiment of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiment of the present invention.

[0036] See also Figure 1-3 :

[0037] A heat sink design model is constructed. The model consists of a baseplate, multiple heat sink fins, the air ducts formed between the fins, and a heat dissipation step below the baseplate. The baseplate length and width are determined by the length and width of the embedded core module. The baseplate thickness is set at 1.5mm, the heat sink fin thickness is set at 0.8mm, and the air duct width is set at 2.5mm. These three dimensions are the optimal solution obtained after multiple experimental iterations. When 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, the embedded core module heat sink design cycle can be shortened, the heat sink design quality can be improved, and the development of embedded core module heat sinks can bring benefits.

[0038] 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:

[0039] 1) Based on the radiator design model, the "natural cooling and forced air cooling heat dissipation evaluation" algorithm is used to evaluate whether the radiator needs a fan design. The calculation process is as follows:

[0040] 1) Estimate the number of air ducts. The calculation process is as follows:

[0041] Number of air ducts = baseboard width / (air duct width + radiator fin thickness)

[0042] =41.5÷(2.5+0.8)=12

[0043] 2) Calculate the effective surface area of ​​the fins of the radiator. The calculation process is as follows:

[0044] The effective surface area of ​​the radiator fins = [2*(estimated radiator fin height*radiator fin thickness) + 2*(estimated radiator fin height*base plate length) + radiator fin thickness*radiator fin length]*(number of ducts+1) + duct width*base plate length*number of ducts

[0045] =[2*(15*0.8)+2*(15*60.5)+0.8*60.5]*(12+1)+2.5*60.5*12

[0046] =26351.2mm 2

[0047] 3) Ignoring the effect of the heat dissipation step on the radiator surface area, calculate the effective surface area of ​​the substrate. The calculation process is as follows:

[0048] Substrate effective surface = 2*(substrate width*substrate thickness)+2*(substrate length*substrate thickness)+substrate length*substrate width

[0049] =2*(41.5*1.5)+2*(60.5*1.5)+60.5*41.5

[0050] =2816.75mm 2

[0051] 4) Add the effective surface area of ​​the fins and the baseplate calculated in 2) and 3) above to get the effective surface area of ​​the radiator. The calculation process is as follows:

[0052] Radiator effective surface area = radiator fin effective surface area + substrate effective surface area

[0053] =26351.2+2816.75=29167.95mm 2 =291.6795cm 2

[0054] 5) Calculate the heat flux density of the radiator. The calculation process is as follows:

[0055] Radiator heat flux density = estimated power consumption of embedded core module / effective surface area of ​​radiator

[0056] =10÷291.6795=0.034W / cm 2

[0057] 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.

[0058] 7) Take the fin height of the radiator as 15mm, and add the radiator base plate thickness (known quantity) and the radiator step thickness (known quantity) to obtain the recommended radiator design height. The calculation process is as follows:

[0059] Recommended radiator design height = radiator fin height + radiator base plate thickness + radiator cooling step thickness

[0060] =15+1.5+2=18.5mm

[0061] 2. Requirement 2: The maximum power consumption of an embedded core module is 10W, and the length and width are 60.5*41.5mm (same as 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:

[0062] 1) Estimate the number of air ducts, which is 12 based on requirement 1:

[0063] 2) Calculate the effective surface area of ​​the fins of the radiator. The calculation process is as follows:

[0064] The effective surface area of ​​the radiator fins = [2*(estimated radiator fin height*radiator fin thickness) + 2*(estimated radiator fin height*base plate length) + radiator fin thickness*radiator fin length]*(number of ducts+1) + duct width*base plate length*number of ducts

[0065] =[2*(10*0.8)+2*(10*60.5)+0.8*60.5]*(12+1)+2.5*60.5*12

[0066] =18382.2mm 2

[0067] 3) Ignoring the effect of the heat dissipation step on the radiator surface area, calculate the effective surface area of ​​the substrate, which is 2816.75mm based on requirement 1. 2

[0068] 4) Add the effective surface area of ​​the fins and the baseplate calculated in 2) and 3) above to get the effective surface area of ​​the radiator. The calculation process is as follows:

[0069] Radiator effective surface area = radiator fin effective surface area + substrate effective surface area

[0070] =18382.2+2816.75=21198.95mm 2 =211.9895cm 2

[0071] 5) Calculate the heat flux density of the radiator. The calculation process is as follows:

[0072] Radiator heat flux density = estimated power consumption of embedded core module / effective surface area of ​​radiator

[0073] =10÷211.9895=0.047W / cm 2

[0074] 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 heat sink fin height is 10mm, the "Forced Air Cooling" (with fan design) cooling method should be selected for the heat dissipation design.

[0075] 7) Based on the "Forced Air Cooling Radiator Design" algorithm requirements, further refine requirement 2, obtain the ambient temperature Q to be 85°C, the maximum housing temperature of the heat dissipation device to be 110°C, and select a fan with a minimum air pressure of 5.34 mm-H2O (approximately 52.46 Pa) and a minimum air volume of 0.13 m3 / min.

[0076] 8) Calculate the radiator air volume requirement. The calculation process is as follows:

[0077] L=Q / (ρCpΔt)=(10 / 1000) / (1.1*1.005*(110-85))=0.000362m 3 / min

[0078] 9) Using the fan's air volume-wind resistance function, calculate the wind resistance at the intersection of the radiator's estimated air duct characteristic curve and the cooling fan's characteristic curve (optimal operating point), as follows:

[0079] R=-WpL+Cq=-0.13*0.000362+52.46=52.46Pa

[0080] 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:

[0081] Rs=bw1 / [2(w1+b)]=10*b / [2*(10 / 100+b)]=5b / (0.1+b)

[0082] 11) The average air velocity in the radiator duct is calculated as follows, where b is the unknown quantity to be calculated:

[0083] =L / (60cw1b)=0.000362 / (60*(10 / 100)*b)=0.000362 / 6b

[0084] 12) Combine the process quantities in 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: ->[0.022*(0.000362 / 6b)2*1.18*(60.5 / 100)] / {4*[5b / (0.1+b)]*2}=52.46

[0085] Solving the above equation, we get b is approximately equal to 12.2 mm

[0086] 13) Based on requirement 2 and the above calculation process, the minimum height of the radiator fins is 12.2mm. This means that the estimated radiator fin height of 10mm cannot be met, and the radiator fin height should be designed to be greater than 12.2mm.

[0087] 14) Take the fin height of the radiator as 12.2mm, and add the radiator base thickness (known quantity) and the radiator step thickness (known quantity) to obtain the recommended radiator design height. The calculation process is as follows:

[0088] Recommended radiator design height = radiator fin height + radiator base plate thickness + radiator cooling step thickness

[0089] =12.2+1.5+2=15.7mm.

[0090] The above are merely 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 description 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 heat sink fins, air ducts formed between the heat sink fins, and a heat dissipation step below 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 H1, the heat sink fin thickness is set to H2, and the air duct width is set to W1. Step 2: Evaluate natural cooling and forced air cooling according to the "natural cooling and forced air cooling heat dissipation evaluation" algorithm, which includes: The radiator power consumption is preset, and the radiator fin height is estimated. Then, based on the existing conditions of the radiator in the radiator model, the effective surface area of ​​the radiator fins is calculated. The heat flux density of the radiator is then calculated by the ratio of the preset radiator power consumption to the effective surface area of ​​the radiator fins. Finally, the calculated heat flux density is compared with the heat flux density threshold. If the calculated heat flux density is not less than the threshold, forced air cooling is used and step 3 is executed. If the calculated heat flux density is less than the threshold, natural cooling is used. Step 3: Obtain a recommended radiator height value based on a "forced air cooling radiator design" algorithm; the "forced air cooling radiator design" algorithm is based on the radiator's air duct characteristic curve and the cooling fan characteristic curve, including: constructing a fan air volume-wind resistance function based on the radiator's air volume requirement and wind resistance requirement, obtaining the radiator wind resistance requirement at the intersection of the radiator's air duct characteristic curve and the cooling fan characteristic curve based on the radiator's air volume requirement data, and then constructing an equation based on the curve intersection with the radiator fin height as a variable and the existing conditions of the cooling fan and radiator as constants. After solving the equation, the recommended radiator fin height value is obtained, and the recommended radiator height value is obtained by adding the radiator fin height to the radiator base plate thickness and the radiator heat dissipation step thickness.

2. The 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 heat sink fin thickness H2 is set to 0.8 mm, and the air duct width W1 is set to 2.5 mm.

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

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

5. The simple design method for a low-cost embedded core module heat sink according to claim 4 is 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 required working environment temperature of the radiator; Sub-step 32: Formula 1, based on the heat balance equation, calculate the radiator air volume requirement. Formula 1 is as follows: Where Q is the maximum system power consumption of the heat sink, which is a known quantity in kW, Δt is the difference between the maximum case temperature of the heat sink and the operating ambient temperature, which is a calculated known quantity in °C, ρ is the air density of 1.1 kg / m³, Cp is the specific heat of air of 1.005 kJ / (kg·°C), and L is the actual air volume required by 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 Where L is the radiator air volume requirement obtained in Formula 1, which is the process variable calculated in Formula 1; Wp is the minimum air volume of the selected cooling fan, which is a known quantity provided by the cooling fan specifications, and the 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 specifications, and the unit is Pa; R is the radiator wind resistance requirement obtained at the intersection of the radiator's air duct characteristic curve and the cooling fan characteristic curve based on the radiator air volume requirement data, which is a process variable, and the unit is Pa; Sub-step 34: Formula 3, calculate the equivalent hydraulic radius of the radiator duct as follows: Where: W1 is the width of the air duct, b is the height of the radiator fins, and is the unknown quantity to be determined; Sub-step 35: Formula 4 calculates the average flow rate of air in the duct as follows: Where c is the number of air ducts, which is the process variable obtained by the method in "Sub-step 21" in the "Natural Cooling and Forced Air Cooling Evaluation" algorithm above. The constant 60 is used for unit conversion to convert the final average flow rate from m³ / s to m³ / min, facilitating the conversion of this data to units consistent with the cooling fan air volume in m³ / min. W1 is the air duct width, a known quantity, and b is the radiator fin height, an unknown quantity to be determined. Sub-step 36: Formula 5, construct the equation with the cooling fan and radiator as known quantities and the radiator height as an unknown quantity, as follows: in is the friction coefficient, which is 0.022, is the air density, y is the fin length, 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, and 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 radiator fin height. Finally, add the radiator fin height, the radiator base plate thickness, and the radiator heat dissipation step thickness to obtain the recommended radiator height.

Images