JPH08189909A - Method and device for simulating heat flow characteristic - Google Patents

Abstract

PURPOSE: To effectively carry out detailed analysis through highly accurate analysis method by storing the data shown by a three-dimensional solid/surface method, and selecting either of a high-speed analysis method by heat network method and liquid network method and that by differential method. CONSTITUTION: Boundary data such as an enumeration data showing the shape of an objective space within an electronic equipment, etc., an enumeration data including the generated heat quantity of a heat source and its location, and the ventilation condition of the boundary part in the objective space are inputted by an inputting means 1. The inputted enumeration data are stored as a data shown by the three-dimensional solid/surface method in a storing device 4. An analysis method selection means 3 selects either of a high-speed analysis method 5a using a heat network method 12a and liquid network method 12b and a high-speed analysis method 5b using a differential method 12c, according to the set condition. Then, a calculation means 5 performs calculation based on the stored data by the selected method and indicates the analyzed result in a display 7.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat flow characteristic simulation method and apparatus for displaying a temperature distribution of a heat flow in a box (target space) equipped with a heat source such as an electronic device and its direction with time. is there.

[0002]

2. Description of the Related Art Conventionally, in a thermo-fluid analysis of a target space in an electronic device, the target space is divided into small regions and a thermal analysis is performed by mathematical modeling. It has been known. In addition, in today's remarkable product cycle, a thermal circuit method and a fluid network method, which are modeled by thermal resistance and perform high-speed analysis with relatively rough division, have been used.

For example, a conventional heat flow characteristic analyzing apparatus for performing highly accurate processing shown in FIG. 20 uses a difference method 12c, a finite element method, or the like, and a target space as shown in FIG. By performing the analysis by dividing, an accurate calculation result can be obtained, but on the other hand, the analysis device requires a huge amount of time for the calculation work. The difference method is a method of dividing the object space into cubic small areas and performing a mathematical approximation called a difference to the heat conduction equation for heat conduction to obtain the solution of the equation, while the finite element method is the object space. Is divided into cubic small regions (finite elements), and for example, the heat conduction equation for heat conduction is replaced with simultaneous linear equations to mathematically find the solution of the equation.

On the other hand, the conventional heat flow characteristic analyzing apparatus shown in FIG. 19 which performs processing at high speed uses the thermal circuit network method 12a and the fluid circuit network method 12b to obtain a rough result by high speed processing by relatively rough division. It is an analyzing device to obtain. The thermal circuit method is a method in which the target space is divided into a mesh shape, and the contact points are represented by the thermal resistance 14 shown in FIG. The method is a method in which the target space is divided into meshes, the pressure difference between each contact point is expressed as a flow path resistance, and the flow velocity of the air flowing in the flow path is modeled as an electric circuit for analysis.

Further, a heat flow characteristic analysis device (Japanese Patent Laid-Open No. 4-30270), which combines the thermal circuit method and the fluid circuit method, has been proposed. In these methods, the shape of the target space is determined. The input count data such as the heat generation amount of the heat source and the arrangement position of the heat source uses the three-dimensional wire frame mathematical method that expresses the shape of the object only by connecting points and straight lines using an orthogonal grid (mesh). It was what was there.

[0006]

In the above-mentioned conventional analysis method, the input data such as the shape is expressed by the three-dimensional wire frame method in which the shape is expressed only by the connection of points and straight lines.

Therefore, in the wire frame method, it is difficult to catch the object as a wall in the hollow portion surrounded by the line. For example, the influence of the radiant heat propagating in the air as electromagnetic waves on the wall surface is calculated from the radiation ratio (form factor). 15 for visually calculating a radiation calculation, checking the contact state between surfaces between surfaces and the state of interference between them, or adding / subtracting graphics (graphic calculation processing) shown in FIG. 14, and visually expressing a three-dimensional shape. In the display using the processing of the hidden line 15 and the hidden surface 16 shown in (3), it is difficult to perform complicated shapes and detailed analysis between the complicated objects only by the points 17 and the lines 18. That is, in the three-dimensional representation of a shape, there is a problem in that a hollow surface is regarded as a wall to perform accurate heat calculation and visually process a complicated three-dimensional shape.

Further, the difference method and the finite element method are excellent in analysis accuracy because the thermal analysis is performed by mathematical modeling, but the target space must be divided into small regions for analysis.
There has been a problem that a huge amount of time is required for calculation processing.

Furthermore, a high-speed analysis method that does not require a calculation processing time due to a relatively rough division such as a thermal circuit method or a fluid circuit method that analyzes by thermal resistance gives a coarse result in accuracy, and the simulation result shows that However, analysis accuracy was insufficient and detailed images could not be obtained, which was a problem.

In order to solve the above-mentioned conventional problems, the present invention uses a three-dimensional solid / surface method to detect a three-dimensional object by combining surfaces and performs calculation and display, and is narrowed down by a simulation by a high-speed solution method. It is an object of the present invention to provide a heat flow characteristic simulation method and apparatus capable of efficiently performing detailed analysis by a high-precision solution method by effectively utilizing input data under suitable conditions.

[0011]

In order to solve the problems of the above-mentioned conventional example, the first invention of the present application is the boundary between the target space and the count data including the shape of the target space, the heat generation amount of the heat source and the arrangement position thereof. From the boundary conditions such as ventilation conditions of the part, in the heat flow characteristic simulation method for obtaining and displaying the heat flow characteristics of the target space over time, the counting data and the boundary conditions are input to an analyzer, and the input counting data is obtained. 3
The data is stored in a storage device as data represented by the three-dimensional solid / surface method, and the analysis device divides the target space into a high-speed solution method using a fluid circuit network method and a thermal circuit network method according to the set analysis conditions. Select one of the high-precision solution methods using the difference method for mathematical analysis,
It is characterized in that an arithmetic operation is executed based on the stored data by using the selected solution and the analysis result is displayed on the display device.

It is preferable that the high-speed solution method and the high-precision solution method have a thermal radiation calculation function or a sensitivity analysis function.

Here, the thermal radiation calculation function is a function of calculating the effect of the amount of heat that the radiant heat propagating in the air as an electromagnetic wave from the heat source has on the wall surface from the radiation ratio (form factor). Further, the sensitivity analysis function is a function in which the size (opening ratio) of inflow / outflow holes such as a boundary surface is provided as a sensitivity parameter, and analysis is performed while freely changing those parameters.

It is also preferable to output the analysis result as a color contour diagram, a vector diagram or a particle diagram.

Here, the color contour diagram expresses the spread of heat in the space by the flow of colors from a bright color to a dark color, and the vector diagram shows the spread of heat in the space. The relationship between the position, the direction and the flow rate is expressed in a vector manner, and the particle diagram described above expresses the flow of the trajectory of the fine particles as a temporal change as if the particles spread the spread of heat to the space.

In order to solve the problems of the above-mentioned conventional example, the second invention of the present application includes count data including the shape of the target space, the amount of heat generated by the heat source and its position, and the ventilation conditions at the boundary of the target space. In a heat flow characteristic simulation device for obtaining and displaying a heat flow characteristic of a target space with time from a boundary condition, an input means for inputting the count data and the boundary condition, and the input count data for the three-dimensional solid /
Either a high-speed solution method using the thermal network method and the fluid network method, or a high-precision solution method using the difference method, depending on the storage device that saves the data represented by the surface method and the set analysis conditions. And a display device for displaying an analysis result, a solution selection means for selecting a solution method, a calculation means for executing an operation based on the stored data in the selected solution method, and a display device for displaying an analysis result. And

[0017]

The first invention of the present application can perform the following operations by the above method. That is, the input data or the data represented by the three-dimensional solid / surface method is stored in a storage device, and the high-speed solution method by the thermal network method and the fluid network method and the high-precision solution method by the difference method are solved. In addition, by executing the operation with the solution method selected by the solution selection means that selects one of the solution methods, the analysis accuracy is not sufficient but the high speed of the thermal network method and the fluid network method that can be handled relatively easily If the simulation is performed by the solution method, the solution can be quickly obtained, and the conditions can be narrowed down to relatively suitable conditions in a short time. If the high-precision solution method by the highly accurate difference method is performed again under the preferable conditions thus obtained,
It is possible to easily and efficiently perform highly accurate thermo-fluid calculation without re-inputting data such as shape and thermo-fluid conditions from scratch.

This is achieved by storing the data in the storage device in the data structure under the same conditions of the solid / surface method for the high-speed solution method and the high-precision solution method.

In addition, by using a data structure based on a three-dimensional solid / surface method, a complex shape expression and detailed information can be obtained by using a wall, such as checking a contact surface state or an interference state, a graphic calculation process, and a display using a hidden surface process. Analysis can be easily performed.

Further, the high-speed solution method and the high-accuracy solution method represent a three-dimensional object by connecting points, lines, surfaces, and surfaces with a data structure based on a three-dimensional solid / surface method if it has a thermal radiation calculation function or a sensitivity analysis function. Then, by catching the surface as a wall, the thermal radiation calculation function can calculate (radiation calculation) from the radiation ratio (form factor) the effect that the wall has on radiation heat propagating in the air as an electromagnetic wave.
While freely changing sensitivity parameters such as the size (opening ratio) of holes such as inlets and outlets with the sensitivity analysis function, changes in heat quantity and heat flow at desired cross-sectional positions can be immediately known.

If the analysis result is to be output as a color contour diagram, a vector diagram, or a particle diagram, the spread of heat in the space is represented by a color flow from a bright color to a dark color, as shown in FIG. Figure or the vector diagram shown in Fig. 17 expressing the relationship between the position, direction and flow rate of the heat spread to the space, or the trajectory of the particles drawn as if the particles spread the heat spread to the space. With an output such as the particle diagram shown in FIG. 18 expressed as a change with time, even a technician having no specialized knowledge of thermodynamics can easily understand the simulation result of thermal analysis.

The second invention of the present application has
Similar to the invention, in the three-dimensional representation of the shape, by treating the surface as a wall, visually processing a complicated three-dimensional shape, combining a high-speed calculation method that roughly calculates and a high-precision calculation that performs final confirmation, The function of simulating the thermo-fluid calculation efficiently and accurately can be performed.

[0023]

Embodiments of the present invention will now be described in detail with reference to the drawings. In the embodiment of the present invention shown in FIGS. 1 to 11, the count data representing the shape of the target space 9, the count data including the calorific value of the heat source 8 and its arrangement position, and the boundary such as ventilation conditions at the boundary portion of the target space. Input means 1 for inputting conditions and storage device 4 for storing the input count data as data represented by a three-dimensional solid / surface method.
And a solution selection for selecting one of the high-speed solution method 5a using the thermal network method 12a and the fluid network method 12b or the high-precision solution method 5b using the difference method 12c according to the set analysis conditions. With means 3 and the solution chosen above,
Arithmetic means 5 for performing an arithmetic operation based on the stored data
And a display device 7 for displaying the analysis result. The shape of the target space 9 such as in the electronic device, the heat generation amount of the heat source, the arrangement position, the count data such as the shape, and the boundary portion of the target space 9 The present invention relates to a simulation device that obtains the heat flow characteristics of the target space 9 over time from boundary conditions such as ventilation conditions.

The input device 1 shown in FIG. 1 is used to input data and process commands. The input data or command is once taken in by the input data processing unit 2, and the echo of the input data or the command processing result is displayed on the display device 7.

Here, the target space 9 of the electronic device shown in FIG. 7 which is the first simulation target is a 200 × 100 × 50 mm enclosure covered with a 2 mm thick iron plate. 10x5x with power IC etc.
A heat source 8 of a printed circuit board modeled as 5 mm is incorporated.

Therefore, in order to input data to the input device 1, first, according to the analysis condition menu shown in FIG. 2 in the analysis condition processing unit 2a, data such as dimension = three-dimensional, convection = natural convection, calculation method = high-speed calculation, etc. Is entered.

Subsequently, according to the shape data menu of FIG. 3, the dimensions of the enclosure X = 200, Y = 100, Z = 50,
Input of external dimensions of W = 2 and selection of physical properties (selecting iron automatically sets physical properties such as iron density, specific gravity and heat transfer coefficient). The shape data processing unit 2b of the component is input. In the first simulation target, the only internal component is the heat source 8,
The dimensions X = 10, Y = 5, Z = 5 and the arrangement position X = 1
Input 00, Y = 50, Z = 2, and calorific value = 100W.

Further, the input of the data of the boundary condition menu in the boundary condition processing unit 2c is 0 data for each item of the menu shown in FIG. 4 because the enclosure has no heat dissipation port in the first simulation target. Enter.

The input data is converted into data of the three-dimensional solid / surface method by the analysis condition processing unit 2a, the shape data processing unit 2b or the boundary condition processing unit 2c of the input data processing unit 2 and displayed on the display device 7. At the same time, it is saved in the input data of the storage device 4 and the data input area 4a of the three-dimensional solid / surface.

The solution selection means 3 selects the high-speed calculation means 5a of the calculation means 5 according to the calculation method = high-speed calculation set in the analysis condition processing part 2a.

In the high speed computing means 5a, the thermal circuit method 12a is used.
And the fluid circuit method 12b, arithmetic processing is performed using the input data and the three-dimensional solid / surface data stored in the input data area 4a of the storage device 4, and the calculation result is stored in the output data area 4b of the storage device 4. Store.

When the arithmetic processing is completed, the simulation processing section 6 creates screen data to be displayed on the display device 7 as data of the three-dimensional solid / surface method while referring to the data in the output data area 4b of the storage device 4.

As a display example of the output result, for example, if the operator specifies the color contour diagram and the display cross-section position data in the pull-down menu, the color contour diagram at the desired cross-section position shown in FIG. 8 can be obtained.

In this way, the operator can obtain the simulation result in a short time by the high speed solution method 5a.

Further, from the above result, the heat generation of the printed circuit board is
If it is found that the life of the capacitor on the printed circuit board 8 is significantly impaired, it is necessary to find suitable conditions by the high speed solution method 5a. Therefore, the second simulation is performed by attaching the heat dissipation port (exhaust port with exhaust fan) 11a and the heat dissipation port (intake port) 11b shown in FIG. 9 to the upper surface and the side surface of the enclosure of the electronic device which is the first simulation target. .

Therefore, from the input means 1 to the analysis condition processing section 2
The convection of a is changed to convection = forced convection, and the boundary condition processing unit 2c further inputs the data of the heat radiation port 11a according to the menu of FIG. In the second simulation,
The heat dissipation port 11a forming the exhaust port with the exhaust fan has a shape of X = 20, Y = 20, and an arrangement position X = 100, Y = 5.
0, Z = 50, aperture ratio = 0.5, flow rate = 0.4, direction =
It is represented by OUT. Then, in the next display menu shown in FIG.
Shape X = 20, Y = 20, arrangement position X = 200, Y =
50, Z = 2, aperture ratio = 0.5, flow velocity = 0. It should be noted that the flow velocity = 0 means that the heat dissipation port 11
b shows that there is no active forced flow velocity, and FIG.
It is not necessary to specify the direction (IN / OUT) shown in (1), and the heat dissipation port 11b is calculated as natural convection and functions as an intake port in this simulation.

The other conditions are the same as those in the first simulation, and the changed data is stored in the input data area 4a of the storage device 4. After that, the same operation as described above is performed by the high speed solution method 5a to obtain the output result shown in FIG.

When the result of the above second simulation shows that the temperature rise in the enclosure is sufficiently suppressed by the effect of the heat dissipation port (exhaust port with exhaust fan) 11a, for example, the sensitivity analysis function is used to detect the heat dissipation port 11a and the like. Hole size (aperture ratio)
While freely changing the sensitivity parameters such as in the pull-down menu, you can immediately know how the heat quantity and heat flow at the desired cross-section position change.

Further, it is possible to reduce the exhaust capacity of the exhaust port with an exhaust fan and to obtain a result such that replacement with an inexpensive small capacity one has little effect, so that more suitable conditions can be narrowed down.

Therefore, it is necessary to perform a highly accurate inspection as a final confirmation.

The third simulation is performed by inputting the data of the small capacity exhaust fan represented by the heat radiation port 11a 'shown in FIG. 11 in place of the heat radiation port 11a of the housing of the electronic device which is the second simulation object. Is to do.

Therefore, from the input means 1, the calculation method of the analysis condition processing unit 2a of the menu of FIG. 2 is set to the calculation method = high accuracy calculation, and the flow velocity data of the menu of the boundary condition processing unit 2c shown in FIG. Change to data representing a small capacity exhaust fan as 0.1.

Other conditions are the same as in the second simulation, and the changed data is stored in the input data area 4a of the storage device 4.

According to the calculation method = high-precision calculation set in the analysis condition processing section 2c, the analysis selecting means 3 and the calculating means 5
Select the high-precision solution method 5b of The computing means 5 refers to the input data in the input data area 4a and the three-dimensional solid / surface data stored in the same storage device 4 as the data referred to in the high-speed solution method 5a, and performs the computation process of the difference method 12c. This calculation effectively uses the input data at the time of high-speed solution to reduce the burden on the operator, but it requires a calculation time because the calculation is performed with high accuracy.
It is used to collect accurate data for final confirmation.

Thereafter, in the same manner as described above, when the arithmetic processing is completed, the simulation processing section 6 refers to the data in the output data area 4b of the storage device 4 and displays the image data as the data of the three-dimensional solid / surface method on the display device 7. To create.

On the display device 7, the final confirmation can be made by obtaining the simulation result shown in FIG. 11, for example. Therefore,
It is also possible to print these simulation results at a time interval on a color printer or the like and save them as design materials.

As described above, in the heat flow characteristic simulation apparatus of this embodiment, the same data can be used based on the result calculated by the high speed solution method 5a to perform the calculation by the high precision solution method 5b. Further, since the shape is created with a three-dimensional solid / surface, it is possible to check the interference of the object to be calculated and display the hidden line processing. Therefore, it is possible to perform accurate heat calculation and suppress the incorrect shape creation. Therefore, the operator does not need to check the shape, and the burden can be reduced.

In the present embodiment, the calculation results are displayed on the screen in the color contour diagram, but they may be displayed in the vector diagram, the particle diagram, or another display. Further, although the shape data is input by the menu method shown in FIG. 2, drawing data such as CAD may be directly input. That is, the present invention is not limited to the above embodiments, and various modifications can be made based on the spirit of the present invention, and these modifications are not excluded from the scope of the present invention.

[0049]

According to the present invention, a three-dimensional solid / surface method is used as a combination of surfaces to calculate and display a three-dimensional object, and a suitable condition narrowed down by a simulation by a high-speed solution method is input. It is possible to provide a heat flow characteristic simulation method and apparatus capable of efficiently performing detailed analysis by a highly accurate solution method by effectively utilizing data.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing an input example of analysis conditions.

FIG. 3 is an explanatory diagram showing an input example of shape data.

FIG. 4 is an explanatory diagram showing an input example of a first boundary condition.

FIG. 5 is an explanatory diagram showing an input example of a second boundary condition.

FIG. 6 is an explanatory diagram showing an input example of other boundary conditions.

FIG. 7 is a configuration diagram showing a first simulation target.

FIG. 8 is an explanatory diagram showing the results.

FIG. 9 is a configuration diagram showing a second simulation target.

FIG. 10 is an explanatory diagram showing the results.

FIG. 11 is an explanatory diagram showing a third simulation result.

FIG. 12 is a configuration diagram showing a mathematical model.

FIG. 13 is a configuration diagram showing a method of analyzing thermal resistance.

FIG. 14 is a configuration diagram showing a graphic logic operation.

FIG. 15 is a configuration diagram showing hidden lines and hidden surfaces.

FIG. 16 is a perspective view showing a color contour diagram.

FIG. 17 is a perspective view showing a vector diagram.

FIG. 18 is a perspective view showing a particle diagram.

FIG. 19 is a block diagram of a fast solution method showing a conventional example.

FIG. 20 is a block diagram of a high-precision solution method showing a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 input means 2 input data processing section 2a analysis condition processing section 2b shape data processing section 2c boundary condition processing section 3 solution selection means 4 storage device 4a input data area 4b output data area 5 solution method 5a high-speed solution means 5b high-precision solution means 6 Simulation processing unit 7 Display device 8 Heat source 9 Target space

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yayoi Kubo 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (7)

[Claims] 1. A heat flow characteristic of a target space is obtained over time from count data including a shape of the target space, a heat generation amount of a heat source, and an arrangement position thereof, and boundary conditions such as ventilation conditions at a boundary portion of the target space. In the heat flow characteristic simulation method of displaying, the counting data and the boundary condition are input to an analysis device, and the input counting data is stored in a storage device as data represented by a three-dimensional solid / surface method. Is either a high-speed solution method that uses the fluid network method and the thermal network method, or a high-precision solution method that uses the difference method to subdivide the target space and perform mathematical analysis according to the set analysis conditions. Heat flow characteristic simulation characterized by selecting, executing the calculation based on the stored data using the selected solution, and displaying the analysis result on the display device. Law. 2. The heat flow characteristic simulation method according to claim 1, wherein the high-speed solution method and the high-precision solution method have a heat radiation calculation function. 3. The heat flow characteristic simulation method according to claim 1, wherein the high speed solution method and the high accuracy solution method have a sensitivity analysis function. 4. The heat flow characteristic simulation method according to claim 1, 2 or 3, wherein the analysis result is displayed in a color contour diagram. 5. The heat flow characteristic simulation method according to claim 1, 2 or 3, wherein the analysis result is displayed in a vector diagram. 6. The heat flow characteristic simulation method according to claim 1, 2 or 3, wherein the analysis result is displayed in a particle diagram. 7. The heat flow characteristic of the target space is obtained over time from the count data including the shape of the target space, the heat generation amount of the heat source and the arrangement position thereof, and boundary conditions such as ventilation conditions at the boundary of the target space. In a heat flow characteristic simulation device for displaying, input means for inputting the count data and the boundary condition, and a storage device for storing the input count data as data represented by a three-dimensional solid / surface method are set. According to the analysis conditions, a high-speed solution method using the thermal network method and the fluid network method, or a solution selection means for selecting one of the high-precision solution methods using the difference method, and the selected solution method, A heat flow characteristic simulation device comprising: a calculation unit that executes a calculation based on the stored data; and a display device that displays an analysis result. .