Method for judging the degree of blockage of an air outlet of an air-cooled power supply system

Abstract

The application provides a method for judging the degree of blockage of an air outlet of an air-cooled power supply system, and belongs to the field of thermal simulation calculation. Boundary conditions of the air-cooled power supply system are set in a simulation system, the ventilation rate is set to 0.1, the module temperature T1 and the outlet air temperature T2 are obtained based on fluid dynamics calculation, the allowable temperature T of the module is set x , the alarm temperature T2' of the air outlet is obtained according to an empirical formula, the empirical formula is T2'=T2+aΔT, wherein ΔT represents the difference between the allowable temperature T x of the module and the module temperature T1, ΔT=T x -T1, a represents a set margin, and a∈[1 / 5,1 / 2]; the ventilation rate is sequentially increased from 0.1 to 1 according to a set threshold value for thermal simulation calculation, and a relationship curve of the alarm temperature T2' of the air outlet and the ventilation rate is fitted; and the degree of blockage of the air outlet of the air-cooled power supply system is judged based on the relationship curve of the alarm temperature T2' of the air outlet and the ventilation rate, so that the blockage condition of the system can be accurately and quickly judged.

Description

Technical Field

[0001] The present invention relates to the field of thermal simulation calculation technology, and in particular to a method for judging the blockage degree of an air outlet of an air-cooled power supply system. Background Art

[0002] For air-cooled power supply systems, a temperature monitoring point is often set on the heat sink baseplate to monitor the temperature of the modules on the heat sink. Generally, through actual product testing, if the temperature of the monitoring point is found to be too high, a system analysis is performed to find the cause of the high temperature. Usually, the monitoring temperature alarm value is fixed, and the relationship between the system ventilation condition and the module temperature is not designed. Therefore, it is impossible to determine the blockage status of the system air inlet and outlet through real-time temperature detection.

[0003] The paper "Research on Heat Dissipation Performance of Nuclear-Grade DCS Chassis Equipment and Analysis of Influencing Factors" (Li Huaqiao et al., Xi'an Jiaotong University, School of Energy and Power Engineering, etc., Journal of Chongqing University of Technology (Natural Science), 2023) shows a negative correlation between ventilation rate and chip temperature. The temperature of the chip is affected by many factors, which may be poor contact of interface materials, poor soldering of pads, abnormal current, etc. The paper focuses on the chip temperature, while there are many reasons for the overheating of the radiator in the air-cooled power supply system. Since the paper did not pay attention to the outlet temperature, it was unable to determine that the overheating of the radiator was caused by the blockage of the outlet. Summary of the Invention

[0004] The technical problem to be solved by the present invention is how to accurately and quickly determine the blockage degree of the air outlet of an air-cooled power supply system.

[0005] The present invention solves the above technical problems through the following technical solutions: a method for determining the blockage degree of the air outlet of an air-cooled power supply system, comprising the following steps:

[0006] Step 1: Set the boundary conditions of the air-cooled power supply system in the simulation system, including the ambient temperature , heat consumption Q , material properties, fan characteristics, three-dimensional physical models of each component and initial environmental pressure;

[0007] Step 2: Set the ventilation rate to 0.1 and calculate the module temperature based on fluid dynamics. , outlet air temperature , set the module allowable temperature , the outlet alarm temperature is calculated according to the empirical formula , the empirical formula is:

[0008]

[0009] in, Indicates the module's allowable temperature and module temperature The difference between , a Indicates the setting margin, ;

[0010] Step 3: Increase the ventilation rate from 0.1 to 1 according to the set threshold value and perform thermal simulation calculation to obtain the outlet alarm temperature. Relationship curve with ventilation rate;

[0011] Step 4: Alarm based on air outlet temperature The relationship curve between the ventilation rate and the ventilation rate is used to determine the blockage degree of the air outlet of the air-cooled power supply system.

[0012] Preferably, the module temperature is obtained based on computational fluid dynamics calculation in step 2. , outlet air temperature include:

[0013] Input the boundary conditions of the air-cooled power supply system into the simulation software, divide the simulation model grid into multiple small grids, obtain the mass conservation equation, momentum conservation equation and energy conservation equation of all small grids based on fluid dynamics, calculate the temperature, pressure and velocity of all positions in the simulation model, and then obtain the module temperature , outlet air temperature .

[0014] Preferably, the step three includes:

[0015] Determine whether the ventilation rate value is less than 1. If so, add the ventilation rate value to the set threshold and return to step 2 to recalculate the outlet alarm temperature , until the ventilation rate value is equal to 1, the calculation ends, and the ventilation rate and module temperature are output. , air outlet alarm temperature .

[0016] Preferably, the step 4 includes:

[0017] Install temperature sensors at the air outlet and power module of the air-cooled power system to read the module temperature and air outlet temperature of the air-cooled power system. Calculate the air outlet alarm temperature based on the empirical formula. , alarm temperature at the air outlet Find the corresponding ventilation rate on the relationship curve with ventilation rate , according to the ventilation rate Determine the degree of blockage of the air outlet.

[0018] Preferably, the setting margin a The value is 1 / 3.

[0019] Preferably, the threshold value range in step three is set to 0.05-0.2.

[0020] Preferably, the air-cooled power supply system includes a power module, a control module, a radiator and a fan. The power module, the control module and the radiator are all located in the power supply box. There is an air inlet at one end of the power supply box and an air outlet at the other end. The fan is located at the air outlet.

[0021] The advantages of the present invention are:

[0022] The present invention performs thermal simulation calculation on the ventilation rate of the air-cooled power system from 10% to 100%, and obtains the relationship (relationship curve) between the air outlet alarm temperature and the ventilation rate in the product design stage, and uses the allowable temperature and module temperature The difference between the air outlet temperature and the ventilation rate is used to set the sum of the margin and the outlet temperature as the alarm protection value. The outlet alarm temperature fed back by the system operation is used to find the corresponding ventilation rate value on the relationship curve. Since the outlet temperature and the ventilation rate respond almost directly, the system blockage situation can be accurately and quickly judged. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 A schematic diagram of an air-cooled power supply system provided in an embodiment of the present invention;

[0024] Figure 2 A flow chart of a method for determining the degree of blockage of an air outlet of an air-cooled power supply system provided by an embodiment of the present invention;

[0025] Figure 3 A curve diagram showing the relationship between the air outlet alarm temperature and the ventilation rate in the method for determining the degree of air outlet blockage in an air-cooled power supply system provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0026] To make the objectives, technical solutions, and advantages of the present invention more clearly understood, the following describes the technical solutions of the present invention in a clear and complete manner with reference to specific embodiments and the accompanying drawings. It is apparent that the embodiments described are only a portion of the embodiments of the present invention, not all of them. All other embodiments obtained by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0027] like Figure 1As shown, this embodiment provides a method for determining the degree of blockage in the air outlet of an air-cooled power supply system. This method can calculate a relationship curve between the air outlet alarm temperature and the ventilation rate during the product design phase, and based on this relationship curve, determine the blockage of the air outlet of the air-cooled power supply system. The air-cooled power supply system includes a power module 20, a control module, a heat sink 30, and a fan 40. The power module 20, control module, and heat sink 30 are all located in a power supply housing 10. The power supply housing 10 has an air inlet at one end and an air outlet at the other end. The fan 40 is located at the air outlet.

[0028] like Figure 2 As shown, the judgment method includes the following steps:

[0029] Step 1: Set the boundary conditions of the air-cooled power supply system in the simulation system, including the ambient temperature , heat consumption Q , material properties, fan characteristics, three-dimensional physical models of each component and initial environmental pressure.

[0030] Step 2: Set the ventilation rate to 0.1 and calculate the module temperature based on computational fluid dynamics. , outlet air temperature , set the module allowable temperature , the outlet alarm temperature is calculated according to the empirical formula , the empirical formula is:

[0031]

[0032] in, Indicates the module's allowable temperature and module temperature The difference between , a Indicates the setting margin, .

[0033] The present invention sets the margin a The value of is 1 / 3.

[0034] Module temperature and outlet temperature It is calculated based on the specific power box boundary input through simulation software based on computational fluid dynamics (CFD) (such as icepak).

[0035] Grid the model to be solved, divide the model into enough small grids (such as 1 million), and calculate the basic differential equations of fluid dynamics (CFD) for all small grids. The temperature, pressure and velocity at all positions in the entire model can be obtained, and the module temperature can be read. and outlet temperature The basic differential equations of fluid dynamics (CFD) consist of the mass conservation equation (continuity equation), momentum conservation equation, and energy conservation equation.

[0036] Step 3: Increase the ventilation rate from 0.1 to 1 according to the set threshold value and perform thermal simulation calculation to obtain the outlet alarm temperature. The relationship curve with ventilation rate.

[0037] Determine whether the ventilation rate value is less than 1. If so, add the ventilation rate value to the set threshold and return to step 2 to recalculate the outlet alarm temperature , until the ventilation rate value is equal to 1, the calculation ends, and the ventilation rate and module temperature are output. , air outlet alarm temperature The threshold value is set to a range of 0.05-0.2. The smaller the threshold value is, the more accurate the calculation result is. The threshold value of the present invention is set to 0.1.

[0038] Step 4: Alarm based on air outlet temperature The relationship curve between the ventilation rate and the ventilation rate is used to determine the blockage degree of the air outlet of the air-cooled power supply system.

[0039] Temperature sensors are installed at the air outlet and power module of the air-cooled power system to detect and read the module temperature and air outlet temperature of the air-cooled power system in real time. The air outlet alarm temperature is calculated according to the empirical formula. , alarm temperature at the air outlet Find the corresponding ventilation rate on the relationship curve with ventilation rate , according to the ventilation rate Determine the degree of blockage of the air outlet.

[0040] Working principle:

[0041] For air-cooled systems, when the system's air inlet and outlet are blocked or unobstructed, the temperature change of the power module is generally greater than the outlet temperature change. If the outlet temperature is used as the alarm temperature, it may not accurately protect the module operation. This paper performs thermal simulation calculations on air-cooled power systems with ventilation rates ranging from 10% to 100%. During the product design phase, the relationship (relationship curve) between the outlet alarm temperature and ventilation rate is obtained, as shown in Figure 2. Figure 3 As shown, the allowable temperature and module temperature The difference between T The sum of / 3 and the outlet temperature is used as the alarm protection value. The outlet alarm temperature fed back by the system operation is used to find the corresponding ventilation rate value on the relationship curve. Since the outlet temperature and the ventilation rate respond almost directly to each other, the system blockage situation can be directly judged, and the user can be notified in time to clean the inlet and outlet to extend the service life.

[0042] The above examples are only used to illustrate the technical solutions of the present application, but not to limit the present application; although the present application has been described in detail with reference to the foregoing examples, those ordinarily skilled in the art should understand: the technical solutions recorded in the foregoing examples can still be modified, or some technical features can be replaced equivalently; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for determining the blockage degree of the air outlet of an air-cooled power supply system, characterized in that: include: S1. Set the boundary conditions of the air-cooled power supply system in the simulation system, including the ambient temperature , heat consumption Q , material properties, fan characteristics, three-dimensional physical models of each component and initial environmental pressure; S2, ventilation rate is set to 0.1, module temperature is calculated based on fluid dynamics , outlet air temperature , input the boundary conditions of the air-cooled power system into the simulation software, divide the simulation model grid into multiple small grids, obtain the mass conservation equation, momentum conservation equation and energy conservation equation of all small grids based on fluid dynamics, calculate the temperature, pressure and velocity of all positions in the simulation model, and then obtain the module temperature , outlet air temperature ; Set the module's allowable temperature , the outlet alarm temperature is calculated according to the empirical formula , the empirical formula is: in, Indicates the module's allowable temperature and module temperature The difference between , a Indicates the setting margin, ; S3. Increase the ventilation rate from 0.1 to 1 according to the set threshold value and perform thermal simulation calculation to obtain the outlet alarm temperature. Relationship curve with ventilation rate; S4. Alarm based on air outlet temperature The relationship curve between the air outlet and ventilation rate is used to determine the blockage degree of the air-cooled power supply system: temperature sensors are installed at the air outlet and power module of the air-cooled power supply system respectively, and the module temperature and air outlet temperature of the air-cooled power supply system are read. The air outlet alarm temperature is calculated according to the empirical formula. , alarm temperature at the air outlet Find the corresponding ventilation rate on the relationship curve with ventilation rate , according to the ventilation rate Determine the degree of blockage of the air outlet.

2. The method for determining the blockage degree of the air outlet of an air-cooled power supply system according to claim 1, characterized in that: S3 includes: Determine whether the ventilation rate value is less than 1. If so, add the ventilation rate value to the set threshold and return to step S2 to recalculate the outlet alarm temperature. , until the ventilation rate value is equal to 1, the calculation ends, and the ventilation rate and module temperature are output. , air outlet alarm temperature .

3. The method for determining the blockage degree of the air outlet of an air-cooled power supply system according to claim 1, characterized in that: The setting margin a The value is 1 / 3.

4. The method for determining the blockage degree of the air outlet of an air-cooled power supply system according to claim 1, wherein: The threshold range is set in S3 to 0.05-0.

2.

5. The method for determining the blockage degree of the air outlet of an air-cooled power supply system according to claim 1, characterized in that: The air-cooled power supply system includes a power module, a control module, a radiator and a fan. The power module, the control module and the radiator are all located in a power supply box. There is an air inlet at one end of the power supply box and an air outlet at the other end. The fan is located at the air outlet.

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