JP2006177870A - Apparatus and method for analyzing heat of heat exchanger, and program for making computer execute the method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily compute and display temperature distributions (especially, taking into account the temperature distributions in the windward and the leeward directions of a fan for cooling a heat sink) of a heat exchanger in heat analysis of heat exchangers, such as heat sinks. <P>SOLUTION: This heat analysis apparatus for computing the temperature distribution in the direction of a prescribed surface of the heat exchanger includes a windward/leeward temperature distribution computing means for determining a one-dimensional temperature distribution T(X) of the heat exchanger in a direction X of a cooling medium flowing in one direction, in parallel with the prescribed surface of the heat exchanger. The windward/leeward temperature distribution computing means includes computations for deriving T(X), through the use of a coefficient of heat transfer of a system comprising both the surface of the heat exchanger and the cooling medium. It is especially preferable that the computations for deriving T(X) be performed, on the basis of a model acquired by dividing the prescribed surface into a plurality of regions and T(X) in each region by a prescribed approximated analytical expression. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a heat analysis apparatus for a heat exchanger that calculates effective temperature parameters and the like at the time of heat design of the heat exchanger, a heat analysis method for the heat exchanger, and a program that causes a computer to execute the method.

  In the business of heat exchangers such as heat sinks and heat pipes, it is considered that not only the quality and price of the product itself, but also the ability of thermal design occupies an important position regarding orders. That is, when designing a heat exchanger, it is necessary to determine the material, shape and size, and to estimate the heat dissipation capability. The heat dissipation capability of the heat exchanger is usually obtained by performing a thermal analysis simulation on a computer. It is also desirable for the user side to be able to immediately confirm the specifications such as the heat dissipation characteristics of the heat exchanger having a desired shape and size and compare the performance.

  Thermal analysis simulation is realized by applying an analysis method such as a difference method or a finite element method to a heat conduction problem.For example, in an example in which the finite element method is applied, an analysis target is divided into a plurality of triangular elements, The temperature is determined so that the heat equation is best satisfied within each element. Therefore, software that realizes a thermal analysis simulation is required to obtain a solution of a large number of heat conduction equations (differential equations) related to accuracy.

  Most of the thermal analysis simulation software used in the past is composed of three programs called a preprocessor, a solver, and a postprocessor. A preprocessor is a program that models a heat sink that is subject to thermal analysis. Data in a format that can be input to the solver in response to input such as information about the size and material of the heat sink, information about the heating element, and conditions for heat removal Output the set.

  The solver is a program that reads a data set output from a preprocessor and calculates simultaneous solutions of a large number of the above-described heat conduction equations. The post-processor is a program that visually displays a solver calculation result, which is merely an enumeration of numerical values, using a temperature table, a temperature distribution chart, or the like.

  Such thermal analysis simulation software is not only large in its execution program size. Since it is necessary to obtain solutions of thousands of simultaneous differential equations, it is usually executed on a relatively expensive computer equipped with a high-speed processor.

On the other hand, a program for simulation software capable of performing thermal analysis in a relatively short time compared to the prior art has been developed. In the field of heat exchangers such as heat sinks, for example, there is a thermal analysis program as shown in Patent Document 1.
JP 2002-319786 A

However, the conventional thermal analysis simulation software as described above is
1) Skill is necessary for operation.
2) Operation is complicated.
3) Calculation time is required.
4) Due to equipment and calculation time, it is difficult to respond at the conference table.
5) There is nothing that can easily calculate and display the two-dimensional temperature distribution of the heat sink (especially, considering the temperature distribution in the windward and leeward direction of the fan that cools the heat sink).
There were problems such as.

Due to the above problems, the following inconvenience has occurred in the business of developing and selling heat exchangers.
1) When the sales representative receives a request to change the specifications of the heat exchanger at the customer's site, in order to present the cooling effect after changing the specifications, the thermal analysis is performed again using the thermal analysis simulation software described above. And a faster answer was sought.
2) The thermal analysis simulation took too much time, and the design took a lot of time.

  In addition, there is a temperature difference in the windward and leeward direction of the fan that cools the heat exchanger, and in particular the temperature tends to increase in the leeward direction. Since there is an adverse effect, it is particularly important to understand the temperature difference between the windward and leeward direction of the fan in actual use.

  By designing the heat so that the temperature difference between the windward and leeward directions is kept at a low value, the temperature difference between the heat exchanger and the cooling medium at the leeward position can be increased, resulting in the performance of the heat exchanger. Can be increased. Therefore, it is extremely effective in designing the heat exchanger that the temperature difference between the windward and leeward directions can be easily obtained.

  The present invention has been made in view of the above, and it is a heat exchanger that reduces the amount of calculation and speeds up the operation by modeling and mathematically solving the behavior of the heat transfer in the solid and the cooling medium. It is an object of the present invention to provide a thermal analysis device, a heat analysis method for a heat exchanger, and a program for causing a computer to execute the method.

In order to achieve the above object, a heat analysis apparatus for a heat exchanger according to the present invention is a heat analysis apparatus that calculates a temperature distribution in a predetermined plane direction of a heat exchanger.
The thermal analysis device is used to determine the one-dimensional temperature distribution T (X) of the heat exchanger for the direction X of the cooling medium flowing in one direction parallel to the predetermined surface of the heat exchanger. The upwind / downwind temperature distribution calculation means includes a calculation means for calculating T (X) using a heat transfer coefficient of a system composed of the heat exchanger surface and a cooling medium. It is a heat analysis device of a heat exchanger.

  The calculation for deriving T (X) is particularly preferably performed based on a model obtained by dividing the predetermined plane into a plurality of regions and approximating T (X) with a predetermined analytical expression in each region.

The number of the plurality of regions is 2, and the predetermined analytical expression is:
The position where the cooling medium flows into the heat exchanger is X = −X ₁ , the position where the cooling medium flows out of the heat exchanger is X = + X ₁ ,
In interval -X1 ≦ X ≦ 0, T = p (X + X ₁ ) ² + q-pX ₁ ² (1)
In the interval 0 ≦ X ≦ + X1, T = p (XX ₁ ) ² + q + pX ₁ ² formula (2)
(However, p and q are coefficients determined by the heat transfer coefficient of the system consisting of the heat exchanger surface and the cooling medium, the amount of heat generated from the heating element, the heat dissipation area of the heat exchanger, and the cross-sectional area in the surface direction of the heat exchanger. It is more preferable that it is represented by.

  The present invention can be widely used for general heat exchangers, but is particularly suitable for thermal analysis of a heat sink in which a plurality of radiating fins are attached to a base that contacts a heating element.

When the present invention is used for the heat analysis of the heat sink as described above, the heat transfer coefficient of the heat exchanger of the base part only modeled by including the heat transfer coefficient of the heat radiating fin part in the heat transfer coefficient of the base part. A heat transfer coefficient calculating means for calculating;
A first circular shape having the same area as the main surface area of the base portion and a second circular shape having the same area as the contact area of the heating element are derived, and the heat exchanger is Modeling means for modeling one circular shape and the second circular shape into a shape arranged as concentric circles;
Temperature calculating means for calculating the temperature distribution of the heat sink modeled by the modeling means;
Is preferably provided.

  According to the heat analysis apparatus and the heat analysis method of the heat exchanger according to the present invention, the two-dimensional temperature distribution of the heat exchanger such as a heat sink (particularly, the windward / downward direction of the fan that cools the heat sink) Can be easily calculated and displayed, and the design of the heat exchanger is facilitated.

  Below, the thermal analysis apparatus of the heat exchanger which concerns on this invention, the thermal analysis method of a heat exchanger, and the program which makes a computer perform the method are demonstrated in detail. In addition, this invention is not limited by this embodiment.

  Embodiment 1 First, a heat analysis device and a heat analysis method for a heat exchanger according to Embodiment 1 will be described. The thermal analysis method of the present invention obtains the temperature distribution of a predetermined surface of a heat exchanger, and its simplest case uses the surface of a heat radiating plate on a flat plate as the predetermined surface. In the heat analysis apparatus for a heat exchanger according to the first embodiment, a heating element is arranged at the center of a flat plate-like heat radiation plate, a cooling fan is arranged at one end side in the longitudinal direction of the heat radiation plate, and cooling toward the other end is performed. It is characterized in that the temperature distribution of the heat radiating plate when the medium is flowing can be derived without performing complicated calculations in consideration of the temperature difference between the windward and leeward.

  FIG. 1 is a block diagram illustrating a schematic configuration of a heat analysis apparatus for a heat exchanger according to the first embodiment. The heat analysis apparatus for a heat exchanger shown in FIG. 1 includes an input unit 11, a temperature distribution calculation unit 18, and a display unit 17, and an upwind / downwind temperature difference calculation process between the input unit 11 and the temperature distribution calculation unit 18. A unit 12 and a temperature calculation processing unit 13 that does not take into account the difference between the windward and leeward temperatures are provided in parallel.

  The input unit 11 is a means for inputting various input parameters necessary for thermal analysis, executing instructions, and the like, and is a keyboard or other pointing device. In particular, here, the input unit 11 inputs heat generation data 21 related to a heating element that is a cooling target of the heat dissipation plate, plate data 22 related to the heat dissipation plate, and environmental data 24 related to a fan or the like attached to one end of the heat dissipation plate. The

  The upwind / downwind temperature difference calculation processing unit 12 includes a heat transfer coefficient calculation unit 23 and an upwind / downwind temperature calculation unit 26 in consideration of the upwind / downwind.

  The heat transfer coefficient calculation unit 23 taking into consideration the windward and leeward is means for calculating the heat transfer coefficient of the system composed of the plate surface and the cooling medium using at least the plate data 22 and the environment data 24 described above. The windward / leeward temperature calculation unit 26 stores in advance the heat transfer coefficient calculated by the heat transfer coefficient calculation unit 23 in consideration of the windward / downwind, the heating element data 21, the plate data 22, and the environment data 23 described above. It is a means for calculating the temperature difference between the windward and leeward of the heat radiating plate using the calculated equation.

  As will be described later, the method for calculating the temperature difference between the windward and leeward according to the present invention is performed based on only a few analytical arithmetic expressions, so that the result can be obtained much faster than the conventional calculation method. .

  The temperature calculation processing unit 13 that does not consider the difference between the windward and leeward temperatures can use conventional temperature calculation means, and is not particularly limited in the first embodiment, but is particularly preferable in the second embodiment described later. Will be described later.

  The temperature distribution calculation unit 18 adds the temperature data output from the upwind / downwind temperature difference calculation processing unit 12 and the temperature calculation processing unit 13 that does not consider the upwind / downwind temperature difference, thereby calculating the temperature of the heat radiating plate. It is a means for calculating the distribution.

  The display unit 17 is means for displaying the data calculated by the temperature distribution calculation unit 18 in a tabular form or a graph, and is a CRT display, LCD, or the like.

  In the following, of the operation of the heat analysis apparatus of the heat exchanger, a part related to the windward / leeward temperature calculation means, that is, a method for calculating the windward / leeward temperature distribution will be described.

First, the operator inputs data on the heat radiating plate to be analyzed. Of the data for the radiating plate, the data relating to the calculation of the windward-leeward temperature distribution, the length of the radiating plate M, the heat radiating area S _e, the cross-sectional area S 'and thermal cut in perpendicular to the windward-leeward direction Conductivity k. Data regarding these heat radiation plates is stored as the plate data 22 described above.

  Further, the operator inputs data on the heating element to which the heat radiating plate is attached. Of the data on the heating element, the data relating to the calculation of the windward and leeward temperature distribution is the heating value Q of the heating element and is stored as the heating element data 21 described above.

  Further, the operator inputs data related to the environment. Among the data related to the environment, the data related to the calculation of the windward and leeward temperature distribution includes the wind speed V of the cooling medium provided by the fan attached to one end of the heat radiating plate, and the laminar flow / Another of turbulence. These are stored as the environmental data 24 described above. Note that whether the laminar flow / turbulent flow is selected by the operator as appropriate.

  When the above data input is completed, the thermal analysis process is started. As a result of the thermal analysis process, a temperature T (X) at a position X in the cooling medium direction of the heat radiating plate is calculated. T (X) is a relative temperature, and this T (X) plus the temperature distribution that does not take into account the difference between the windward and leeward temperatures is shown in Fig. 1 as the temperature distribution on the predetermined surface of the heat exchanger. Displayed on the display unit 17. T (X) may be displayed in a table format or may be displayed in a graph as shown in FIG.

  Next, features of the thermal analysis process in the present invention will be described.

[Characteristics of Thermal Analysis Processing in the Present Invention] As shown in FIG. 2, the present inventor has shown that the leeward side (area 1) and the leeward side ( It was found that the temperature distribution in each region can be approximated by the following quadratic expression by dividing the region into two regions. In the following equation, T ₁ (X) is the temperature at the position X in the leeward region, and T ₂ (X) is the temperature at the position X in the leeward region. X ₁ is the distance from the center (X = 0) to the end of the heat radiating plate (that is, the distance from the windward and leeward) (X ₁ = 1/2 × M).

T ₁ (X) = p (X + X ₁ ) ² + q-pX ₁ ² Formula (1-1)
T ₂ (X) =-p (XX ₁ ) ² + q + pX ₁ ² Formula (1-2)
The reason why the temperature distribution of the heat dissipation plate can be approximated as described above is that the gradient of the temperature distribution is the maximum near the center of the heat dissipation plate, that is, the heat flow, as a result of examination using a precise simulation using the finite element method etc. This is because the bundle is the highest and the gradient of the temperature distribution at the end of the heat radiating plate is almost 0, that is, the heat insulation state is almost obtained.

The coefficients p and q in the equations (1-1) and (1-2) are the heat transfer coefficients a ₁ and a _{2 of} the system composed of the heat radiating plate and the cooling medium in the above regions 1 and 2, It can be expressed using the thermal conductivity k of the heat radiating plate and the cross sectional area S ′ of the heat radiating plate. The following describes how to obtain p and q.

First, the heat transfer coefficients a ₁ and a ₂ of a system composed of a heat radiating plate and a cooling medium are obtained as follows. a _{1 (laminar flow)} is a heat transfer coefficient when it is assumed that the cooling medium on the surface of the heat dissipation plate is laminar. V is the wind speed of the cooling medium.

a _{1 (laminar flow)} = {∫ ₀ ^{M / 2} 1.93√ (V / X) dx} / (M / 2) Equation (2-1)
a _{2 (laminar flow)} = {∫ _{M / 2} ^M 1.93√ (V / X) dx} / (M / 2) Equation (2-2)
In general, the heat transfer coefficient a _{(turbulent flow)} when the flow of the object surface is turbulent is generally expressed by the following equation. Where m is the length of the object.

a _{(turbulent flow)} = 0.037 × Pr ^2/3 Re ^4/5 λ / m (3)
Where Pr is the Prandle number of air, Re is the Reynolds number, and λ is the thermal conductivity of the air.

The heat transfer coefficients a _{1 (turbulent flow)} and a _{2 (turbulent flow)} of the system composed of the heat radiating plate and the cooling medium for regions 1 and 2 when the cooling medium on the surface of the heat radiating plate is assumed to be _turbulent From (3), it becomes as follows.

a _{1 (turbulent flow)} = 0.037 × Pr ^2/3 (M / 2 × V / μ) ^4/5 λ / (M / 2)
= 0.037 × Pr ^2/3 (V / μ) ^4/5 (M / 2) ^4/5 λ / (M / 2)
= 0.037 × Pr ^2/3 (V / μ) ^4/5 λ × (2) ^1/5 × M ^-1/5
a _{2 (turbulent flow)} = 0.037 × Pr ^2/3 (V / μ) ^4/5 λ × (2-2 ^1/5 ) × M ^-1/5
Here, μ is the kinematic viscosity coefficient of air. Note that in the case of natural air cooling (a method in which the medium is moved only by the buoyancy of the cooling medium without using power such as a fan), the buoyancy of the cooling medium is calculated as gQ / TCp, which is the pressure of the cooling medium ( The air velocity V can be determined from the balance of the pressure loss ΔP and the dynamic pressure ρV ² / (2g)) multiplied by the cross-sectional area of the ventilation part (the part through which the cooling medium flows). The heat transfer coefficient of the system can be calculated. Here, Cp is constant pressure specific heat, ρ is air density, and g is gravitational acceleration.

From the equations (1-1) and (1-2), the average temperatures T _{av, 1} and T _{av, 2} in the regions 1 and ₂ are as follows.

T _{av, 1} = q- (2/3) pX ₁ ² formula (4)
T _{av, 2} = q + (2/3) pX ₁ ² formula (5)
Here, the concept of the network method shown in FIGS. 4A and 4B is used for heat exchange. FIG. 4A is a model of the network method. In FIG. 4A, 30 is air, 31 is a heat radiating plate, 31- (1) is region 1 in the heat radiating plate 31, and 31- (2) is region 2. It is shown that heat escapes from each of the regions 1 and 2 to the air 30 and escapes through the thermal resistance at this time. FIG. 4B is a detailed model of the network method shown in FIG. Region 1 and region 2 are indicated by point 31- (1) and point 31- (2), respectively, and both are connected via thermal resistance R. The amount of heat transferred from region 2 to region 1 is represented by Q1. The thermal resistance when heat escapes from the region 1 and the region 2 to the air is represented by Rh1 and Rh2, respectively.

Using this idea of the network method, the following equation holds. Note that _Se is a heat radiation area of the heat radiation plate.

a ₁ S _e T _{av, 1} = Q / 2 + Q ₁ formula (6)
a ₂ S _e T _{av, 2} = Q / 2-Q Formula ₁ (7)
Here, the following relationship is established from the balance of heat conduction in the solid.

Q ₁ = kS '{p (X + X ₁ ) 2}' _{X = 0}
= 2pX ₁ kS 'Equation (8)
Therefore, by substituting Equation (8) into Equation (6) and Equation (7) and solving as simultaneous equations, coefficients p and q in Equations (1-1) and (1-2) representing the temperature distribution of the heat radiating plate are obtained. Can be requested.

_{p = 3 (a 1 -a 2} ) Q / {4X 1 (3a 1 kS '+ 3a 2 kS' + 2a 1 a 2 S e X 1)} Equation (9)
q = {6kS '+ (a ₁ + a ₂ ) S _e X ₁ } Q / {2S _e (3a ₁ kS' + 3a ₂ kS '+ 2a ₁ a ₂ S _e X ₁ )} Equation (10)
The above is the description of the characteristics of the thermal analysis processing in the present invention.

  Further, as a feature of the present invention, after the thermal analysis processing as described above is performed, a graph can be displayed, or a graph in which the graph is incorporated in a contour diagram (temperature distribution diagram) can be displayed. . Further, the amount of heat Q1 moving from the region 2 to the region 1 can be calculated using the equation (8).

  In the first embodiment, the heat radiating plate is handled as the heat exchanger. However, the thermal analysis device and the thermal analysis method of the present invention can be widely applied to general types of heat exchangers. For example, the present invention can be applied to a heat sink having a large number of fins in the base portion. In this case, the base portion is handled as the heat dissipation plate of the model described above. In this case, the value of the cross-sectional area of the heat sink including the fins is used as the cross-sectional area S ′ of the heat radiating plate in the model. In addition, the present invention can also be applied to radiator fins.

  In the first embodiment, the case where the cooling medium is air (wind sent from a fan) has been described. However, the present invention can be applied to the case where the cooling medium is a liquid such as water, and the same effect can be obtained. Is.

  In the first embodiment, the heat radiating plate is divided into two regions, and the temperature distribution in each region is approximated by a quadratic expression such as equations (1) and (2). However, the number of divisions is 3 It is good also as above. In that case, the temperature distribution is approximated by another appropriate function.

  [Embodiment 2] In Embodiment 1, the temperature calculation processing method of the temperature calculation processing unit 13 that does not consider the difference between the windward and leeward temperatures is not specified, but in this Embodiment 2, the heat exchanger is a base surface. An embodiment in which a particularly preferable method is applied to the temperature calculation processing unit 13 that does not consider the windward / leeward temperature difference when the heat sink is provided with a plurality of radiation fins on the upper side will be described.

  In the heat analysis method of the heat exchanger according to the second embodiment, the temperature distribution of the heat sink when the heating element is disposed on the center of the base surface of the heat sink is considered in consideration of the temperature distribution in the windward and leeward direction of the cooling fan. And it is characterized by being able to derive | lead-out correctly, without performing a complicated calculation.

  FIG. 5 is a block diagram illustrating an outline of a thermal analysis device for a heat exchanger according to the second embodiment. The heat analysis apparatus of the heat exchanger shown in FIG. 5 includes an input unit 11, a heat transfer coefficient calculation unit 23 that takes into account the difference between the windward and leeward temperature, Conversion unit 13, upwind / downwind temperature calculation unit 26, temperature calculation unit 14 that does not consider the difference between upwind and downwind temperature, fin information processing unit 15, fan information processing unit 16, temperature distribution calculation unit 18, display unit 17, and calculation An expression storage unit 25 is provided.

  The input unit 11 is a means for inputting various input parameters necessary for thermal analysis and executing instructions, and is a keyboard or other pointing device. In particular, here, the input unit 11 causes the heating element data 21 regarding the heating element to be cooled by the heat sink, the base data 22a regarding the base plate of the heat sink, the fin data 22b regarding the fin of the heat sink, and the cooling attached to one end of the heat sink. Environmental data 24 related to the industrial fan or the like is input.

  The heat transfer coefficient calculation unit 23 and the upwind / downwind temperature calculation unit 26 in consideration of the upwind and downwind are the same as those described in the first embodiment.

  The heat transfer coefficient calculation unit 12 that does not consider the difference between the windward and leeward temperatures uses at least the heating element data 21, the base data 22a, the fin data 22b, and a predetermined heat transfer coefficient derivation formula to calculate the heat transfer coefficient of the fin surface. And means for calculating a heat transfer coefficient converted by modeling described later. The area conversion unit 13 is a means for deriving a cylinder in a state in which the main surface (surface that contacts the heating element) and the side surface area of the base and the area of the main surface (surface that contacts the base) of the heating element are held. is there. In other words, it is a means for replacing the base with a cylinder having the same surface area.

  The temperature calculation unit 14 that does not consider the difference between the windward and leeward temperatures is calculated by the heat transfer coefficient calculation unit 12 that does not consider the difference between the windward and leeward temperatures for the cylindrical heat sink modeled by the area conversion unit 13. It is means for calculating the temperature distribution of the heat sink using the heat transfer coefficient, the heating element data 21, the base data 22a and the fin data 22b, and the arithmetic expression stored in advance in the arithmetic expression storage unit 25. In the arithmetic expression storage unit 25, as the arithmetic expression, the final form of the heat conduction equation established between the inside and the outside of the portion corresponding to the modeled cylindrical heating element, and the energy based on the thermal energy conservation law The balance equation and the heat conduction equation established in the thickness direction of the cylindrical shape described above are stored. In particular, the number of these arithmetic expressions (specifically three) is extremely small as compared with the thousands of heat conduction differential equations required in the conventional thermal analysis simulation software. This is one of the features of the present invention, thereby realizing high-speed thermal analysis. Details of the above-described arithmetic expression will be described later.

  The fin information processing unit 15 is a means for processing information derived for the fin portion such as the fin pitch, the fin interval, and the fin efficiency based on the fin data 22b. Further, the fan information processing section 16 is based on the environmental data 24 such as the front wind speed by the cooling fan attached to one end of the heat sink and the fin information calculated by the fin information processing section 15 and the inter-fin air speed, air volume, and pressure loss. It is means for processing information on the action of the fan such as (pressure loss).

  The temperature distribution calculation unit 18 calculates the temperature distribution of the heat sink by adding the temperature data output from the upwind / downwind temperature difference calculation unit 26 and the temperature calculation unit 14 not considering the upwind / downwind temperature difference. It is means to do.

  The display unit 17 is a means for displaying the data calculated by the temperature calculation unit 14, the fin information processing unit 15 and the fan information processing unit 16 that do not take into account the difference between the windward and leeward temperatures in a tabular format, and is a CRT display or LCD Etc.

  The heat sink thermal analysis apparatus shown in FIG. 5 can be replaced with a general-purpose computer system. In that case, the above-described heat transfer coefficient calculation unit 23 in consideration of upwind / downwind, heat transfer coefficient calculation unit 12 in consideration of upwind / downwind temperature difference, area conversion unit 13, upwind / downwind temperature calculation unit 26, wind The operations of the temperature calculation unit 14, the fin information processing unit 15, the fan information processing unit 16, and the temperature distribution calculation unit 18 that do not consider the temperature difference between the up and down winds are realized by a computer program executed on the CPU of the computer. The arithmetic expressions stored in the arithmetic expression storage unit 25, the heating element data 21, the base data 22a, the fin data 22b, and the environment data 24 are stored in a storage device mounted on the computer.

  The operation of the heat sink thermal analysis apparatus, that is, the heat sink thermal analysis method will be described below. FIG. 6 is a diagram illustrating a display example of data input / output in the heat sink thermal analysis apparatus.

  First, the operator inputs data on the base of the heat sink to be analyzed in the input item table 102 on the screen 100 shown in FIG. Specifically, as shown, the base width, the base length, the base thickness, the thermal conductivity of the base, the specific gravity of the base, and the like. Data regarding these bases is stored as the base data 22a described above.

  Further, in the same input item table 102, data on the fin of the heat sink to be analyzed is input. Specifically, as shown in the figure, the height of the fin, the thickness of the fin, the number of fins, the thermal conductivity of the fin, the specific gravity of the fin, and the like. Data regarding these fins is stored as the fin data 22b described above.

  Further, in the same input item table 102, data on a heating element to which a heat sink is attached is input. Specifically, as shown in the figure, the width of the heating element, the length of the heating element, the amount of heat generation, and the like. Data relating to these heating elements is stored as the heating element data 21 described above.

  Further, in the same input item table 102, the operator inputs data such as the front wind speed brought about by the fan attached to the heat sink and the environmental temperature serving as a temperature reference as the environmental data 24 described above. The front wind speed indicates the wind speed flowing between the fins.

  Further, on the screen 100 shown in FIG. 6, the correspondence between the shape of the heat sink to be analyzed and the input items is displayed in the heat sink display frame 101. In FIG. 6, a heat sink having comb-shaped fins is displayed as an example. In the figure, reference numeral 104 denotes a heating element. By displaying the shape of the heat sink to be analyzed in this way, the definition of input items can be clarified, input errors can be prevented, and the heat sink shape image currently being analyzed can be confirmed. be able to.

  When the data input to the input items shown above is completed, the thermal analysis process is automatically started.

  FIG. 7 is a flowchart illustrating a thermal analysis process performed by the heat sink thermal analysis apparatus according to the second embodiment. Thermal analysis processing by the heat sink thermal analysis device includes thermal analysis processing considering the windward and leeward (flow on the left side in FIG. 7) and thermal analysis processing not considering the temperature difference between the windward and leeward (flow on the right side in FIG. 7). Are performed in parallel.

The thermal analysis process considering the windward and leeward is the same as that described in the first embodiment. That is, the heat transfer coefficient of the system composed of the plate surface and the cooling medium is calculated using the base data 22a, the fin data 22b, and the environment data 24 (step S201), and then, according to the equations (9) and (10) of the first embodiment. It is assumed that the windward and leeward temperature distributions are obtained by calculating p and q and substituting them into equations (1) and (2) (step S202). However, the thermal area S _e, the cross-sectional area of the windward-leeward direction S 'shall use the value that matches the shape of the heat sink.

  Next, the flow of thermal analysis processing that does not consider the difference between the windward and leeward temperatures will be described.

First, the heat transfer coefficient calculation unit 12 that does not consider the difference between the windward and leeward temperatures calculates the fin surface area using the fin data 22a described above (step S101), and calculates the fin surface heat transfer coefficient (step S101). S102). The fin surface area S _fin is calculated using the fin height, fin length (same as base length), fin thickness, and number of fins among the input items shown in FIG.

Further, the heat transfer coefficient calculation unit 12 that does not consider the difference between the windward and leeward temperatures uses the above-described base data 22a, and uses the heat transfer coefficient α _fin of the fin surface calculated in step S102, to calculate the base part and the fin part. The heat transfer coefficient α ′ converted to the base surface is calculated so that the constructed heat sink can be handled as one base (step S103). Specifically, the heat transfer coefficient α ′ is calculated by multiplying the heat transfer coefficient α _fin of the fin by the area magnification of the fin.

  FIG. 8 is an explanatory diagram for explaining the conversion of the heat transfer coefficient and the conversion of the area described later. FIG. 8A shows a heat sink in which the base and the fin are integrated. As described above, in the heat sink thermal analysis apparatus according to the present invention, the heat transfer coefficient of the fin portion is set to the heat transfer coefficient of the base portion. Only the base is subject to thermal analysis. Therefore, at this stage, the shape of the thermal analysis target can be handled as a single plate as shown in FIG. 4B, thereby reducing and simplifying the number of heat conduction equations required for thermal analysis. is doing.

  Subsequently, the heat sink thermal analysis apparatus uses the heating element data 21 and the base data 22a described above for one base modeled as shown in FIG. The area of the (main surface) and the area of the contact portion of the heating element on the base surface are calculated (step S104). Specifically, the area of the base surface (main surface) is calculated using the base width and the base length among the input items, and the area of the contact portion of the heating element is the width of the heating element and the length of the heating element. It is calculated using

として表される。 Then, the area conversion unit 13 derives two circles in a state where the base area and the heating element area calculated in step S104 are held, and calculates the radius of each circle (step S105). In particular, the replacement from the base to the circle realizes a modeling in which the circle corresponding to the heating element is arranged in the center of the circle corresponding to the base, as shown in FIG. 8C. (Step S105). Specifically, in the cylindrical shape shown in FIG. 8C, when the radius of the inner circle is R ₁ and the radius of the outer circle is R ₂ ,

Represented as:

Subsequently, the heat sink thermal analysis apparatus starts thermal analysis, that is, derivation of temperature distribution, with respect to the heat sink modeled in step S105 described above, by the temperature calculation unit 14 that does not consider the windward / leeward temperature difference. Derivation of the temperature distribution by the temperature calculation unit 14 is performed by the heat transfer coefficient α ′ calculated by the heat transfer coefficient calculation unit 12 that does not take into consideration the windward / downwind temperature difference, the heating element data 21, the base data 22a, and the fin data. 22a and an arithmetic expression stored in the arithmetic expression storage unit 25, step S106 for establishing an equation outside the heating element, step S107 for establishing an equation inside the heating element, Step S108 for setting the boundary condition, Step S109 for solving the inner and outer equations of the heating element simultaneously, Step S110 for formulating the modeled heat sink thickness direction, and Step for the boundary condition in the thickness direction Step S111 is set according to the derivation process of simultaneous equations in S109, and step S112 is used to solve the equation in the thickness direction. It is.

  Below, the process of above-mentioned step S106-S112 is demonstrated concretely. In this temperature calculation, paying attention to the point that “heat spreads concentrically”, the temperature distribution is calculated by setting the heat conduction equation for the cylindrical shape shown in FIG. Adjust as a correction value. Note that the cylindrical temperature distribution can be expressed by analytical connection of heat conduction equations that are established on the outer side and the inner side of the region where the heating element is located.

First, the equation outside the heating element (R ₁ ≦ r ≦ R ₂ ), that is, the equation used in step S106 described above will be described. FIG. 9 is an explanatory diagram for explaining equations on the outside and inside of the heating element. As shown in FIG. 9A, the equation outside the heating element corresponds to the radius of the base from r = R ₁ corresponding to the radius of the heating element region 40, with the center of the heating element region 40 being r = 0. Ring regions having a width up to r = R ₂ are of interest.

となる。ここで、θは温度を示し、λはベースの熱伝導率を示し、Ｌは厚さを示し、α'は、上記したステップＳ１０３で算出された換算熱伝達率を示し、ｒは微小部分４１の内径を示す。 In FIG. 9A, paying attention to the concentric minute portion 41 of the ring region, when a differential equation is established assuming that the amount of heat calculated from the change in inclination is equal to the amount of heat deprived,

It becomes. Here, θ indicates the temperature, λ indicates the thermal conductivity of the base, L indicates the thickness, α ′ indicates the converted heat transfer coefficient calculated in step S103 described above, and r indicates the minute portion 41. The inner diameter is shown.

となる。 To organize this,

It becomes.

と置いて、

と置いた級数解法により解を求めることにする。
ｉ）第１の解を求めるステップとして、まず、上記した式（１３）を

と書き下ろし、この式（１４）を上記した式（１１）に代入して整理すると、

が得られる。 here,

And put

The solution is determined by the series solution method.
i) As a step for obtaining the first solution, first, the above equation (13) is obtained.

And substituting this formula (14) into the above formula (11) and rearranging it,

Is obtained.

と求まる。 In order for this equation (15) to always hold, all the coefficients of the same order must be equal. When n is changed, A _n = 0 when n is an odd number, and n ² _An = 4A _n-2 when n is an even number. from now on,

It is obtained.

が得られる。ここで、Ａ₀＝１とおくと、第一種変形ベッセル関数Ｂｅｓｓｅｌ Ｉ（ｒ）に一致する。この解をＪとおく。
ii）つぎに、第２の解を求めるステップとして、

と置く。ｉ）と同様に、この式（１８）を

と書き下ろす。 Therefore, by substituting this equation (16) into the above equation (13),

Is obtained. Here, if A ₀ = 1, it matches the first type modified Bessel function Bessel I (r). Let this solution be J.
ii) Next, as a step for obtaining the second solution,

Put it. Similar to i), this equation (18)

Write down.

が得られる。 When this equation (19) is substituted into the above equation (11), the logarithm term disappears because J is the solution of equation (11). Then substituting J 'and organizing it,

Is obtained.

が得られる。この式（２１）を変形すると、結局、

が得られる。 In this equation (20), when k and n are changed, B _n = 0 when n is an odd number as in i). When n is an even number, k = s, n = 2s, and n = 2 for each term
Substituting s-2 and organizing

Is obtained. If this equation (21) is transformed, after all,

Is obtained.

が得られる。 Furthermore, in this formula (22), if s is changed from 1 to s and added side by side,

Is obtained.

と求められる。 After all,

Is required.

Here, if α ′ = − 1 and B ₀ = −γ, then this corresponds to the second type modified Bessel function Bessel K (r).

と表すことができる。この式（２４）がステップＳ１０６において用いられる方程式であり、演算式記憶部２５にあらかじめ記憶されている。ステップＳ１０６の具体的な処理としては、演算式記憶部２５に記憶された式（２４）を取り出した後、ステップＳ１０３で算出された換算熱伝達率α’やベースデータ２２ａで得られる熱伝導率λ等を用いて、上記した式（２）で表わされるｍを算出し、式（２４）を特定する。なお、Ｃ，Ｄの求め方は、以下の説明において述べる。また、以下の式において、Ｂｅｓｓｅｌ Ｉ（ｘ）は、Ｉ（ｘ）と省略し、Ｂｅｓｓｅｌ Ｋ（ｘ）は、Ｋ（ｘ）と省略して表記する。 Finally, the temperature θ outside the heating element (R1 ≦ r ≦ R2) is expressed by the above-described formula (17) and formula (23) as follows:

It can be expressed as. This equation (24) is an equation used in step S106, and is stored in advance in the arithmetic expression storage unit 25. As a specific process of step S106, after extracting the equation (24) stored in the arithmetic equation storage unit 25, the converted heat transfer coefficient α ′ calculated in step S103 and the thermal conductivity obtained from the base data 22a. Using λ or the like, m represented by the above equation (2) is calculated, and equation (24) is specified. The method for obtaining C and D will be described in the following description. In the following equations, Bessel I (x) is abbreviated as I (x), and Bessel K (x) is abbreviated as K (x).

Next, the equation inside the heating element (0 ≦ r ≦ R ₁ ), that is, the equation used in step S107 described above will be described. As shown in FIG. 9B, the heating element region 40 is targeted for the equation inside the heating element. Here, in FIG. 9B, attention is focused on the concentric minute portion 42 of the heating element region 40.

が得られる。 If the calorific value per unit volume is q ₀ ,

Is obtained.

が得られる。 In this equation (25), the first term on the right side (the term for heat transfer) is significantly smaller than the second term (the term for heat generation), so it is omitted.

Is obtained.

と書けるが、ｒ＝０の時、温度の傾きは０となるので、ｃ＝０となる。 Here, when q ₀ / λ = 4k _con , Equation (26) is

However, when r = 0, the temperature gradient is 0, so c = 0.

と表すことができる。この式（２８）がステップＳ１０７において用いられる方程式であり、演算式記憶部２５にあらかじめ記憶されている。なお、ａ＝−ｋである。 After all, the temperature θ inside the heating element (0 ≦ r ≦ R ₁ ) is

It can be expressed as. This equation (28) is an equation used in step S107, and is stored in advance in the arithmetic expression storage unit 25. Note that a = −k.

で表される。この式のうち、ａ，ｂ，Ｃ，Ｄが未知数であるため、これらの値が
定まれば、目的とするヒートシンクの温度θ_aを得ることができる。 The temperature θ _a of the modeled heat sink is obtained by analytical connection between the above formula (24) and formula (28).

It is represented by Of this equation, since a, b, C, D is unknown, if these values are determined, it is possible to obtain a temperature theta _a heat sink for the purpose.

が成り立つ。 Therefore, a, b, C, and D are obtained (corresponding to step S109) by defining the boundary conditions in the above equations (24) and (28) (corresponding to step S108). First, as the heat insulation condition at the end, at r = R ₂ ,

Holds.

となり、Ｃは、Ｄで表すことができる。ここで、ｋ＝Ｋ'（ｍＲ₂）／Ｉ'（ｍＲ₂）である。なお、Ｋ’（ｍＲ₂）とＩ'（ｍＲ₂）は、通常知られている変形ベッセル関数の計算方法（アレン（Ａｌｌｅｎ）の近似式）を用いて既知の値として導出できるが、ここではその説明を省略する。 That is,

And C can be represented by D. Here, k = K ′ (mR ₂ ) / I ′ (mR ₂ ). Note that K ′ (mR ₂ ) and I ′ (mR ₂ ) can be derived as known values by using a generally known modified Bessel function calculation method (Allen approximation formula). The description is omitted.

が成り立つ。 In order to analyze and connect the above equations (24) and (28) in order to express the temperature inside and outside the heating element with one equation, as a boundary condition, connect smoothly at r = R ₁ . That is, θ in both equations needs to coincide (conservation law of heat quantity). That is,

Holds.

のようにＤで表わされる。 Here, I (mR ₁ ), K (mR ₁ ), I ′ (mR ₁ ), and K ′ (mR ₁ ) should be derived as known values using a commonly known modified Bessel function calculation method. Can do. That is, according to Expression (33) and Expression (31), a is

Is represented by D.

のようにＤで表わされる。結局、上記した係数Ｃ，ａ，ｂはいずれもＤの関数と
して表すことができ、未知数Ｄが定まれば、温度θ_aが求まる。 Also, according to the equation (34), the equation (32), and the equation (31), b is also

Is represented by D. After all, the above-described coefficients C, a, and b can all be expressed as a function of D, and when the unknown D is determined, the temperature θ _a can be obtained.

というエネルギーバランスが成り立つ。この式（３６）に、上記した式（２９）
を代入すると、

が得られる。 Therefore, as a further condition, since the heat dissipation amount of the heat sink needs to match the heat generation amount of the heating element,

The energy balance is established. In this formula (36), the above formula (29)
Substituting

Is obtained.

Q is known as the input item shown in FIG. 6, α ′ is determined in step S103, and a, b, and C are shown in Expression (31), Expression (34), and Expression (35), respectively. because represented by D, as, ultimately, by the equation (37), Sadamari unknowns D, temperature theta _a heat sink is obtained. In addition, the integral calculation of Formula (37) can obtain a solution using the Simpson formula.

Next, a description will be given of establishing a modeled equation in the thickness direction of the heat sink (corresponding to step S110). FIG. 10 is an explanatory diagram for explaining an equation in the thickness direction. As shown in FIG. 10, in the equation of the thickness direction, in a heat sink modeled in a columnar shape, a heat amount Q _i corresponding to the heat generation amount of the heating element enters from above, but the heat amount Q _t that goes out is It is obtained using the conditions of the equations (30), (32), and (33).

とおくと（但し、外周をｕ、断面積をＳとする）、
解は、

と書ける。ここで、ｍ’を場所によらずに一定値となるとして仮定している。 Heat is taken away from the lateral direction, but using a virtual heat transfer coefficient α ”

(Where u is the outer periphery and S is the cross-sectional area)
The solution is

Can be written. Here, m ′ is assumed to be a constant value regardless of the location.

の３つで、変数が３個なので原理的に解ける。 The boundary condition is

Because there are three variables, it can be solved in principle.

If β = 1 / [S × (−λ) × m ′] in the above equation (41), it can be written as e ₂ = e ₁ −βQ _i .

となる。 Therefore, from the above equation (42),

It becomes.

が得られる。 Substituting this equation into equation (43) above,

Is obtained.

  When m′t is large on the left side, it exhibits β, that is, 1 / m ′ behavior (in short, it becomes a graph of the form of y = 1 / x), so it can be said that it is a “good function” for the Newton method.

  When a solution is obtained by the Newton method from where m ′ is sufficiently small, it converges in about 5 times. However, in an actual operation, it is preferable to program 10 times as a precaution.

  The heat sink temperature calculated in this way is obtained as a temperature rise value from the environmental temperature in the second embodiment (step S113). More specifically, the temperature increase value is output as the temperature of the heat sink at the portion where the heating element is in contact, as in the temperature item displayed in the output item table 103 shown in FIG. In addition, in FIG. 6, when there is no heat pipe (HP), when normal quality HP is used, when high quality HP is used, and when using high quality HP, the temperature rise value of the heat sink is shown. it's shown. Thus, by storing in advance several types of HP information whose cooling effect is known, the performance of the heat sink when HP is added can be presented.

  Further, in the output item table 103 shown in FIG. 6, the fin pitch, the fin interval, and the fin efficiency are displayed as information provided from the fin information processing unit 15 described above. In particular, the information related to the fin information is useful as an index indicating the difficulty in actually manufacturing the heat sink.

  In the output item table 103 shown in FIG. 6, spread efficiency is also displayed as information on the base. Here, the spread efficiency is a concept similar to the fin efficiency, and is a dimensionless number indicating how much heat is spread in the base, and is data that can be calculated by a predetermined arithmetic expression based on the base data 22a. .

  Further, in the output item table 103 shown in FIG. 6, the wind speed (front surface), the wind speed (between fins), the air temperature rise value, the air volume, and the pressure loss are displayed as information provided from the fan information processing unit 16 described above. The In particular, this fan information and the information on the heat pipe are not an indicator of the direct performance of the heat sink, but since the fan and heat pipe are likely to be used together when using the heat sink, the presentation of such information is not possible. It becomes useful for the side using the heat sink.

  In addition to the items shown in the output item table 103 of FIG. 6, information on a heat conductive buffer member (silicone grease, silicone rubber, etc.) interposed between the heating element and the heat sink, and an electric heating element ( Information on the Peltier module etc.) may be presented.

  FIG. 11 is an explanatory diagram for explaining the comparison between the thermal analysis result by the conventional simulation software and the thermal analysis result by the present invention. The table shown in FIG. 11A is the size of the heat sink made of copper = 88 [mm] × 64 [mm], fin height = 40 [mm], fin thickness = 0.5 [mm], number of fins = 32 sheets, fin pitch = 2.0 [mm], heating value of heating element = 79 [W], front wind speed = 3.71 [m / s], environmental temperature = 0 ° C, The ratio of the temperature rise value when the thickness and the size of the part where the heating element contacts the heat sink (heat source size) are the conditions shown in the same table, when analyzed by other soft simulations, and the heat sink according to the present invention The case where it analyzed with the thermal-analysis apparatus is shown.

  Moreover, about the temperature rise value analyzed with the heat sink thermal analysis apparatus concerning this invention, the error is also shown simultaneously. Here, the error is calculated as 100 × (difference in temperature rise value) / (reference temperature rise value). FIG. 11B is a graph showing the errors shown in the table of FIG.

  As shown in FIG. 11, both the difference between the analysis result by the other software simulation and the analysis result by the heat sink thermal analysis apparatus according to the present invention and the error with respect to the reference temperature rise value are 3% or less. Considering the effect of realizing high-speed thermal analysis and simple operation, the loss of analysis accuracy lost as a price is negligibly small.

  As described above, according to the heat sink thermal analysis apparatus and the heat sink thermal analysis method according to the second embodiment, the heat sink is modeled into a cylindrical shape that is mathematically easy to handle, and several heats that can be applied to the modeling are modeled. By storing the conduction equation in advance, it is possible to calculate the temperature distribution of the heat sink in a short amount of time, and also to incorporate the effects of the up and down temperature distribution of the cooling fan attached to one end of the heat sink. .

  In particular, the conventional thermal analysis simulation required several minutes to several tens of minutes of analysis time even for a slight change in specifications, whereas the heat sink thermal analysis apparatus according to the present invention simplified the heat conduction equation. Therefore, the analysis can be completed in a few seconds. This means that, for example, when the heat sink thermal analysis device according to the present invention is realized by a portable computer such as a notebook computer, the performance of the heat sink with respect to the specification change can be instantly presented by the customer. . On the other hand, the customer side (user side) can immediately check the heat dissipation characteristics and the like of the heat sinks of various shapes and sizes, so that the heat sink having the optimum specifications desired by the customer can be selected.

  Further, the operations performed by the input / output display shown in FIG. 6 and the various processing units shown in FIG. 5 are processes that can be realized on a so-called office application such as a word processor or spreadsheet software. This makes it possible to use a user interface based on an application familiar to the user, and solves problems such as the necessity and complexity of operation proficiency in conventional thermal analysis simulation software.

It is a block diagram which shows schematic structure of the heat-analysis apparatus of the heat exchanger which concerns on Embodiment 1 of this invention. It is a figure explaining modeling of temperature distribution in the thermal analysis apparatus of the heat exchanger of this invention. It is a figure which shows the example of a result display in the heat-analysis apparatus of the heat exchanger which concerns on Embodiment 1 of this invention. It is a figure explaining the circuit network method employ | adopted with the thermal analysis method of the heat exchanger of this invention. It is a block diagram which shows schematic structure of the heat sink thermal analysis apparatus which concerns on Embodiment 2 of this invention. It is a figure which shows the example of a display of the data input / output in the heat sink thermal analysis apparatus which concerns on Embodiment 2 of this invention. It is a flowchart which shows the thermal analysis process by the heat sink thermal analysis apparatus which concerns on Embodiment 2 of this invention. In Embodiment 2 of this invention, it is explanatory drawing for demonstrating conversion of a heat transfer rate, and conversion of the area mentioned later. In Embodiment 2 of this invention, it is explanatory drawing for demonstrating the equation of the outer side of a heat generating body, and an inner side. In Embodiment 2 of this invention, it is explanatory drawing for demonstrating the equation of a thickness direction. In Embodiment 2 of this invention, it is explanatory drawing for demonstrating the comparison with the thermal analysis result by the conventional simulation software, and the thermal analysis result by this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Input part 12 Heat transfer coefficient calculation part 13 which does not consider an upwind / downwind temperature difference 13 Area conversion part 14 Temperature calculation part 15 which does not consider an upwind / downwind temperature difference 15 Fin information processing part 16 Fan information processing part 17 Display part 18 Temperature Distribution calculation unit 21 Heating element data 22a Base data 22b Fin data 23 Heat transfer coefficient calculation unit 24 considering upwind and leeward Environment data 25 Calculation formula storage unit 26 Upwind / downwind temperature calculation unit 101 Heat sink display frames 102 and 202 Input Item table 103 Output item table

Claims (13)

In the thermal analysis device that calculates the temperature distribution about the predetermined surface direction of the heat exchanger,
The thermal analysis device is used to determine the one-dimensional temperature distribution T (X) of the heat exchanger for the direction X of the cooling medium flowing in one direction parallel to the predetermined surface of the heat exchanger. The upwind / downwind temperature distribution calculation means includes a calculation means for calculating T (X) using a heat transfer coefficient of a system composed of the heat exchanger surface and a cooling medium. Thermal analysis device for heat exchangers. The calculation for deriving T (X) is performed based on a model obtained by dividing the predetermined plane into a plurality of regions and approximating T (X) with a predetermined analytical expression in each region. Item 2. The heat analysis device for a heat exchanger according to Item 1. The number of the plurality of regions is 2, and the predetermined analytical expression is:
The position where the cooling medium flows into the heat exchanger is X = −X ₁ , the position where the cooling medium flows out of the heat exchanger is X = + X ₁ ,
In interval -X1 ≦ X ≦ 0, T = p (X + X ₁ ) ² + q-pX ₁ ² (1)
In the interval 0 ≦ X ≦ + X1, T = p (XX ₁ ) ² + q + pX ₁ ² formula (2)
(However, p and q are coefficients determined by the heat transfer coefficient of the system consisting of the heat exchanger surface and the cooling medium, the amount of heat generated from the heating element, the heat dissipation area of the heat exchanger, and the cross-sectional area in the surface direction of the heat exchanger. The thermal analysis device for a heat exchanger according to claim 2, wherein the thermal analysis device is expressed by: The heat analysis apparatus for a heat exchanger according to any one of claims 1 to 3, wherein the heat exchanger is a heat sink in which a plurality of radiating fins are attached to a base that contacts a heating element. . The heat analysis device for a heat exchanger according to claim 4, wherein the heat analysis device for the heat exchanger further comprises:
Heat transfer coefficient calculating means for calculating the heat transfer coefficient of the heat exchanger of the base part only, which is modeled by including the heat transfer coefficient of the radiating fin part in the heat transfer coefficient of the base part;
A first circular shape having the same area as the main surface area of the base portion and a second circular shape having the same area as the contact area of the heating element are derived, and the heat exchanger is Modeling means for modeling one circular shape and the second circular shape into a shape arranged as concentric circles;
Temperature calculating means for calculating the temperature distribution of the heat sink modeled by the modeling means;
The heat analysis device for a heat exchanger according to claim 4, comprising: When the cooling by the cooling medium is natural cooling, the heat transfer coefficient of the system composed of the surface of the heat exchanger and the cooling medium uses the air speed of the cooling medium obtained from the relationship between the buoyancy and the pressure of the cooling medium. The heat analysis device for a heat exchanger according to any one of claims 1 to 5, wherein the heat analysis device is calculated as follows. In the thermal analysis method for obtaining the temperature distribution about the predetermined surface direction of the heat exchanger,
The thermal analysis method includes an upwind / downwind temperature distribution calculation step for obtaining a one-dimensional temperature distribution T (X) of the heat exchanger with respect to a direction X of the cooling medium flowing parallel to the predetermined surface of the heat exchanger. The upwind / downwind temperature distribution calculating step includes a calculation of deriving T (X) using a heat transfer coefficient of a system composed of the heat exchanger surface and a cooling medium. Thermal analysis method. The calculation for deriving T (X) is performed based on a model obtained by dividing the predetermined plane into a plurality of regions and approximating T (X) with a predetermined analytical expression in each region. Item 7. A heat analysis method for a heat exchanger according to Item 6. The number of the plurality of regions is 2, and the predetermined analytical expression is:
The position where the cooling medium flows into the heat exchanger is X = −X ₁ , the position where the cooling medium flows out of the heat exchanger is X = + X ₁ ,
In interval -X1 ≦ X ≦ 0, T = p (X + X ₁ ) ² + q-pX ₁ ² (1)
In the interval 0 ≦ X ≦ + X1, T = p (XX ₁ ) ² + q + pX ₁ ² formula (2)
(However, p and q are coefficients determined by the heat transfer coefficient of the system consisting of the heat exchanger surface and the cooling medium, the amount of heat generated from the heating element, the heat dissipation area of the heat exchanger, and the cross-sectional area in the surface direction of the heat exchanger. The heat analysis method for a heat exchanger according to claim 7, wherein the heat analysis method is expressed by: The heat analysis method for a heat exchanger according to any one of claims 6 to 8, wherein the heat exchanger is a heat sink in which a plurality of radiating fins are attached to a base that contacts a heating element. . The heat analysis method for a heat exchanger according to claim 9, wherein the heat analysis method for the heat exchanger further includes:
A heat transfer coefficient calculating step for calculating the heat transfer coefficient of the heat exchanger of the base part only, which is modeled by including the heat transfer coefficient of the radiating fin part in the heat transfer coefficient of the base part;
A first circular shape having the same area as the main surface area of the base portion and a second circular shape having the same area as the contact area of the heating element are derived, and the heat exchanger is A modeling step of modeling a circular shape of 1 and the second circular shape into a shape arranged as concentric circles;
A temperature calculating step for calculating a temperature distribution of the heat sink modeled by the modeling means;
The heat analysis method for a heat exchanger according to claim 9, comprising: When the cooling by the cooling medium is natural cooling, the heat transfer coefficient of the system composed of the surface of the heat exchanger and the cooling medium uses the air speed of the cooling medium obtained from the relationship between the buoyancy and the pressure of the cooling medium. The heat analysis method for a heat exchanger according to any one of claims 7 to 11, wherein the heat analysis method is calculated as follows. The program which makes a computer perform the method as described in any one of Claims 7-12.

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