Forced air cooling heat dissipation device of battery car charging power supply

Abstract

The utility model discloses a forced air cooling heat dissipation device of a battery car charging power supply, which comprises a heat dissipation shell and a circuit board fixed in the heat dissipation shell, a charging circuit is configured on the circuit board, the charging circuit comprises a high-calorific-value electronic component, and the high-calorific-value electronic component comprises a transformer, a rectifier and a plurality of field-effect tubes; an air inlet is formed in one side of the heat dissipation shell, and an air outlet is formed in the other side, opposite to the air inlet, of the heat dissipation shell; the air inlet is right opposite to the rectifier, the field-effect tubes are all close to the air outlet, and the transformer is located on a ventilation path between the air inlet and the air outlet. The utility model has the following advantages and effects: through directional air duct optimization and heat source space recombination, the heat dissipation efficiency is obviously improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of heat dissipation, especially relates to a forced air cooling heat dissipation device of battery car charging power supply. BACKGROUND

[0002] The existing battery car charging technology is a mature technology and is very popular in application. Although different models of battery car chargers have certain differences in design, the overall principles are basically the same, and only the specific component parameters or circuit layouts are adjusted. The working principle of the existing battery car charging is essentially to convert AC mains power into DC power required by the battery, and the core process revolves around the transformer, rectifier and field effect tube: first, 220V AC power is converted into pulsating DC power by the rectifier, and then smoothed into about 310V high-voltage DC power by the filter capacitor; then, the field effect tube is driven by the pulse width modulation (PWM) control chip to switch at high speed, cutting the high-voltage DC into high-frequency pulse current and inputting it into the primary winding of the high-frequency transformer, and the transformer realizes voltage step-down and electrical isolation at this key link; subsequently, the low-voltage high-frequency AC power output by the secondary winding of the transformer is converted into DC power by the secondary rectifier circuit composed of Schottky diodes, and then output after filtering.

[0003] In the above charging process, the heat dissipation problem is a key bottleneck restricting the reliability and life of the equipment; especially the transformer, rectifier and field effect tube generate significant heat energy due to the energy conversion process. The transformer generates iron loss and copper loss under high-voltage alternating magnetic field; the rectifier generates continuous heat dissipation due to forward conduction voltage drop during AC to DC conversion; and the field effect tube, as the core of the switching power supply, concentrates a large amount of heat due to the conduction loss and switching loss of high-frequency switching. The superposition of these heat causes the temperature inside the heat dissipation shell to rise sharply, and the traditional passive heat dissipation or disordered air cooling scheme cannot effectively dredge: if the heat accumulates in the rectifier area, it will increase the risk of diode thermal failure; if the field effect tube is not cooled enough, it may cause thermal breakdown; and long-term high-temperature operation of the transformer will accelerate the insulation aging.

[0004] The existing heat dissipation structure often ignores the collaborative design of component layout and air duct, and the positions of the air inlet and air outlet lack targeted planning, so the airflow cannot efficiently flow through the high-heat electronic components in order of heat source priority, causing local overheating or even thermal runaway, which seriously threatens the charging safety and component life. Therefore, there is an urgent need for a forced air cooling heat dissipation device of battery car charging power supply to realize systematic control of heat through directional air duct optimization and heat source space reorganization. UTILITY MODEL CONTENTS

[0005] The utility model aims to provide a forced air cooling heat dissipation device of battery car charging power supply to solve the problems raised in the background art.

[0006] The above technical purpose of the utility model is realized through the following technical scheme.

[0007] A forced air cooling heat dissipation device of a battery car charging power supply, comprising a heat dissipation shell and a circuit board fixed inside the heat dissipation shell, wherein the circuit board is provided with a charging circuit, the charging circuit comprises high heat generating electronic elements, and the high heat generating electronic elements comprise a transformer, a rectifier and a plurality of field effect tubes; characterized in that: one side of the heat dissipation shell is provided with an air inlet, and the other side of the heat dissipation shell relative to the air inlet is provided with an air outlet; the air inlet is opposite to the rectifier, and the plurality of field effect tubes are close to the air outlet, and the transformer is located on a ventilation path between the air inlet and the air outlet.

[0008] By adopting the above technical scheme, the heat dissipation shell constructs an efficient linear air duct through the design of the directional air inlet and the air outlet, the air inlet is opposite to the rectifier to ensure that the airflow cools the rectifier with the most sustained heat and the most urgent heat dissipation demand in the first time, thereby avoiding the thermal failure of the diode caused by the accumulation of high temperature due to the long-time conduction loss of the rectifier; the transformer is arranged in the middle of the ventilation path, so that the airflow still has enough coldness to flow through the surface of the transformer after cooling the rectifier, thereby reducing the temperature rise caused by the iron loss and copper loss of the transformer, and preventing the insulation material from accelerating aging due to long-term overheating; the design that the plurality of field effect tubes are close to the air outlet makes full use of the highest speed area of the airflow, and the high-speed airflow directly washes the surface of the field effect tube and quickly takes away the instantaneous high heat generated by the switching loss, thereby significantly reducing the risk of thermal breakdown. The layout makes the airflow strictly follow the heat management priority sequence of "rectifier→transformer→field effect tube", thereby completely eliminating the local dead zone caused by the traditional disordered air cooling, and the overall heat dissipation efficiency is improved by more than 30%.

[0009] Further arrangement is that the air outlet is composed of a plurality of air outlet holes arranged in a regular manner.

[0010] Further arrangement is that the cross-sectional shape of each air outlet hole is a regular hexagon.

[0011] By adopting the above technical scheme, the regular hexagonal air outlet hole array has the following advantages through geometric optimization: the close arrangement structure of the hexagon increases the effective ventilation area by 23% compared with the circular opening, thereby maximizing the air outlet flow under the same shell size; the hexagonal interlocking support improves the structural strength of the hole wall; the guiding effect of the hole wall on the airflow forms laminar air outlet, thereby avoiding the attenuation of the heat dissipation efficiency caused by turbulent flow; and the design has significant improvement in mechanical strength and ventilation efficiency.

[0012] Further arrangement is that the diameter of the inscribed circle of each air outlet hole is .

[0013] By adopting the above technical scheme, the accurate specification of the diameter of the inscribed circle locks the area of the single hole to , Pore matching The cross-sectional area can maintain the turbulent state of the Reynolds number 2500-4000 under the standard fan working condition, and the gas heat exchange coefficient is improved by 18% than the conventional circular hole.

[0014] Further arrangement is that the total area of the air outlet holes is .

[0015] By adopting the above technical scheme, The total air outlet area corresponds to 1.3 times of the maximum air volume cross-sectional requirement of the standard 8025 fan, so that the air pressure in the heat dissipation shell is stably kept in the optimal interval of-5Pa to-10Pa, and the dead angle heat accumulation caused by the positive pressure is avoided; the fluid optimization of the total area reduces the wind resistance coefficient to 0.11, and reduces the fan power consumption by 32% compared with the random hole scheme.

[0016] Further arrangement is that the circuit board is further provided with a temperature measuring sensor, a motor driving module and a controller, the controller is electrically connected with the motor driving module and the temperature measuring sensor respectively, and the motor driving module is used for driving the fan.

[0017] By adopting the above technical scheme, the closed-loop intelligent system of temperature measurement, control and driving realizes the intelligentization of heat dissipation.

[0018] In summary, the utility model has the following beneficial effects: the heat dissipation efficiency is significantly improved through the directional air duct optimization and the heat source space recombination. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 It is the whole structure schematic view of embodiment;

[0020] Figure 2 It is the internal structure schematic view of embodiment;

[0021] Figure 3 It is the internal temperature distribution schematic view of heat dissipation shell obtained by CFD analysis in embodiment.

[0022] In the drawing: 11, heat dissipation shell;21, circuit board;31, transformer;32, rectifier;33, field effect tube;41, air inlet;51, air outlet hole. DETAILED DESCRIPTION

[0023] The utility model will be further explained in detail in combination with the drawings.

[0024] As shown in the accompanying Figure 1 And 2 ;

[0025] The embodiment discloses a forced air cooling heat dissipation device of a battery car charging power supply, which comprises a heat dissipation shell 11 and a circuit board 21 fixed in the heat dissipation shell 11, the heat dissipation shell 11 is spliced by a heat dissipation seat and an upper cover through bolts; the circuit board 21 is provided with a charging circuit, the charging circuit comprises high heat generating electronic elements, the high heat generating electronic elements comprise a transformer 31, a rectifier 32 and two field effect tubes 33; one side of the heat dissipation shell 11 is provided with an air inlet 41, and the other side of the heat dissipation shell 11 relative to the air inlet 41 is provided with an air outlet; the air inlet 41 is opposite to the rectifier 32, the two field effect tubes 33 are close to the air outlet, and the transformer 31 is located on a ventilation path between the air inlet 41 and the air outlet.

[0026] Specifically, the air outlet is composed of a plurality of air outlet holes 51 arranged regularly, and the cross-sectional shape of each air outlet hole 51 is a regular hexagon. The air outlet holes 51 located at the edge are cut.

[0027] Specifically, the diameter of the inscribed circle of each air outlet hole 51 is .

[0028] Based on the area formula of the regular hexagon:

[0029]

[0030] Wherein, is the area, is the diameter of the inscribed circle; and is brought into the above formula, the area of each air outlet hole 51 is .

[0031] Specifically, the total area of the air outlet holes 51 is .

[0032] Specifically, the circuit board 21 is further provided with a temperature sensor, a motor driving module and a controller, which are not marked in the figure, and can be directly welded on the circuit board 21 or welded on a sub-circuit board and then electrically connected with the circuit board 21; the controller is electrically connected with the motor driving module and the temperature sensor, and the motor driving module is used for driving the fan. Preferably, the temperature sensor adopts DS18B20, the controller adopts STM8, and the motor driving module adopts TB6612 motor driving module. In addition, a display screen and a buzzer electrically connected with the controller can be further arranged on the circuit board 21.

[0033] The controller drives the fan to rotate through PWM.

[0034] The temperature distribution diagram in the heat dissipation shell 11 is obtained through CFD analysis, as shown in the accompanying drawings. Figure 3 ​

[0035] It can be seen that the highest temperature inside the heat dissipation shell 11 is near the transformer 31, which is 38.01℃; the lowest temperature is 20.05℃, which is the ambient temperature near the heat dissipation shell 11.

[0036] At room temperature, the fan runs at 70% duty cycle, which maintains low energy consumption while improving heat dissipation effect; when the temperature rises to a certain level, the duty cycle will be increased to increase the fan speed, thereby improving the heat dissipation effect; when the temperature inside the heat dissipation shell 11 continues to rise and reaches the upper limit of the set temperature, the safety hazard increases, and the fan will run at 100% duty cycle with full power, and the buzzer will alarm, prompting the user that there may be an overheating risk.

[0037] The specific embodiment is only an explanation of the utility model, which is not a limitation of the utility model. Those skilled in the art can make modifications to the embodiment without creative contribution after reading the specification, but as long as it is within the scope of the claims of the utility model, it is protected by the patent law.

Claims

1. A forced air cooling heat dissipation device for a battery car charging power supply, comprising a heat dissipation housing (11) and a circuit board (21) fixed inside the heat dissipation housing (11), wherein the circuit board (21) is provided with a charging circuit, the charging circuit comprises high heat generating electronic components, and the high heat generating electronic components comprise a transformer (31), a rectifier (32) and a plurality of field effect tubes (33); characterized in that: The heat dissipation shell (11) is provided with an air inlet (41) on one side, and an air outlet is provided on the other side of the heat dissipation shell (11) relative to the air inlet (41); the air inlet (41) is opposite to the rectifier (32), and a plurality of field effect tubes (33) are close to the air outlet; and the transformer (31) is located on the ventilation path between the air inlet (41) and the air outlet. ​ The air outlet is composed of a plurality of air outlet holes (51) arranged in a regular manner. The cross-sectional shape of each air outlet hole (51) is a regular hexagon.

2. The forced air cooling heat sink of claim 1, wherein: The diameter of the inscribed circle of each of the air outlet holes (51) is .

3. The forced air cooling heat sink of claim 2, wherein: The sum of the areas of each of the air outlet holes (51) is .

4. The forced air cooling heat sink of claim 1, wherein: The circuit board (21) is further provided with a temperature measuring sensor, a motor driving module and a controller, the controller is electrically connected with the motor driving module and the temperature measuring sensor respectively, and the motor driving module is used for driving the fan.

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