Solution for Noise Reduction of Induction Cooker

Abstract: Noise is always the problem of the induction cooker that haunts people. This paper introduces the solution of reducing the noise of the induction cooker by improving the duct structure with innovatively-designed air duct, fan and air intake grill and heat radiator systems. It will greatly solve the noise problem caused by the induction cooker’s fan and reduce the noise to 32dB (A).

Key words: Induction Cooker; Induction Heating; Air Duct; Heat Radiation; Noise

The induction cooker that is sold on the market at present has a noise of 45dB(A) when using or so, which is equivalent to the ordinary indoor conversation. To reduce the noise, we used: ANSYS, PRO / E, and other software through qualitative calculation, simulation, analysis, and combined with a large number of experiments to verify the study of: induction cooker air duct system, heat dissipation system, and design a new induction stove air duct system and heat dissipation.

The new air duct system and heat dissipation system of the induction cooker was designed to achieve the effect of low noise below 32dB(A). Sound Within 20~40 decibels, quiet, like a whisper.

1. TWO MAJOR DIFFICULTIES

To achieve the desired goal, two seemingly contradictory difficulties must be solved:  (1) the difficulty of noise reduction; (2) and the temperature rise of components.

The noise problem is a long-standing problem of induction cookers where the fan noise accounts for a large proportion. And how to reduce this part of the noise is a difficult point of the project. The second is the difficulty of heat dissipation. To ensure that the noise is being reduced, the components above the electronic control board must be properly maintained.

Operating at a low-temperature rise level is a matter of product quality, long-term reliability, and good service life that also contributes to the difficult points of the project. Because the fan at the air volume of the machine is small, the noise is also small which leads to the temperature rise of the components. If the air volume is large, the can heat dissipates so the noise will increase. Finding the balance between the two is the key to resolving the difficulties.

2. SOLUTIONS

2.1 Duct system

Induction cooker air duct system mainly consists of two major parts: air duct and fan.

The current induction cooker air duct system has an unreasonable distribution of flow field, low air volume utilization rate, and high fan speed (about 2100rad / min) that causes defects in the fan. The air duct system of the current induction cooker has unreasonable flow distribution, low airflow utilization rate, and high fan speed (about 2100 rad/min), which leads to the problem of increased noise of the fan. The air duct system of this project is mainly based from the above-mentioned aspects. 

On the other hand, the new design has a reasonable distribution of flow field, high utilization rate of air volume, and a low fan speed (1270rad/min). Also, the duct system of this project is designed with reasonable flow field distribution, high air volume utilization, low fan speed (1270rad/min), and low noise. 

The main design is as follows:

1）Duct Design

The duct of this project uses Archimedes’ spiral principle to design a new type of spiral type collector duct and adopts the upper and lower buckle sealing structure. The inlet air grille is also newly designed. The air duct makes the flow field distribution more reasonable, improves the utilization of air volume, and reduces the noise to a certain extent.

2) Fan Design

Through qualitative simulation analysis combined with the newly designed air duct, a new fan was designed. 

The newly designed is a five-blade fan (the current domestic induction fan is generally seven blades), with low speed, low noise, large air volume, smooth rotation, uniform air, and with low fan power (about 2W). 

The new fan and air duct structure is shown in Figure 1 and Figure 2:

Figure 1: New Type of Fan

Figure 2:  Air Duct System

3) Air duct flow field simulation results

Through ANSYS simulation, the distribution of air duct flow field of the prototype machine

The air volume is heavily concentrated on the upper side of the air duct air outlet, that is, the air volume is heavily concentrated on the weak part of the induction.The weak part of the main board of the induction cooker, and the weak part of the main board of the induction cooker does not need too much,this will lead to the need for heat dissipation of the strong part of the flow through the wind volume is too small, the strong part of the components temperature rise too high.The temperature rise of the strong part of the components is too high, which affects the service life of the induction cooker. As shown in

Figure 3 New Prototype duct flow field

As shown in Figure 3. Compared with the simulation results of Archimedes spiral duct flow field (qualitative analysis), the distribution shown in Fig. 4 is very good.

(qualitative analysis), we can see from the distribution diagram shown in Figure 4, the new duct flow field distribution is more uniform and reasonable, the air volume is concentrated in the middle of the air duct, closer to the Induction cooker motherboard strong power area, flow through the induction cooker motherboard area air volume increased, so that will reduce the temperature rise of components in the strong power area.

2.2 Heat dissipation system

(1) air duct cooling system

The new design of the induction cooker air duct due to its more reasonable distribution of the flow field (see the upper points), the motherboard’s strong power, weak power area flow through the wind distribution is reasonable, can simultaneously ensure that the motherboard as a whole in the low-temperature state of operation, so that the combination with the whole machine to form a very effective cooling system to solve the problem of temperature rise of components to increase the product life, to ensure the quality of the product. The specific simulation results are shown in Figure 5(qualitative simulation analysis).From Figure 5, it can be seen that the high temperature area (reddish) in the temperature field of the prototype mainly concentrated in the induction cooker main board strong power region and the overall temperature rise level is high, then in this area of the induction cooker components temperature rise is too high, components in the long-term high components in a long-term high temperature rise state operation will affect the life and quality of the product.

As can be seen from Figure 6, the new design of low-noise induction cooker temperature field high temperature area is significantly reduced, the induction cooker motherboard overall temperature rise level is low, so as to ensure that the main board components in the low temperature rise state, can increase the product life, to ensure product high quality.

Figure 4 New air duct flow field

Figure 5 Prototype temperature field distribution cloud

Figure 6  New model temperature field distribution cloud

2）New and efficient heat sink

The new heat sink designed by ourselves has better heat dissipation performance and

faster heat dissipation. This heat sink is mainly for the two key components of IGBT and bridge stack. The heat sink is mainly for the two key components of IGBT and bridge stack, which can ensure the operation of these two key components at low temperature.

The heat sink is designed to dissipate heat from two key components, IGBT and bridge stack. It can ensure the operation of these two key components at low temperature, prolong their service life and increase the overall reliability of the product. Combined with the air duct cooling system and the inlet and outlet air system, it forms the induction combination with the air duct cooling system and the inlet and outlet air system forms the complete heat dissipation system of the induction furnace. The results of the heat sink simulation (see Figure 7). From the temperature field distribution cloud in Figure 7, the high temperature area of the prototype heat sink is mainly concentrated in the position above the IGBT, and the high temperature area is large, and the overall radiator.

The overall temperature of the heat sink is high. From the temperature field distribution cloud diagram in Figure 8, it can be seen that the heat sink of the low-noise model

The distribution of the high-temperature area is roughly the same as that of the original radiator, but the high-temperature area is significantly higher than that of the prototype. The distribution of the high-temperature area of the radiator is significantly smaller than that of the prototype, and the overall temperature rise of the radiator is relatively low.

Figure 6 Prototype heat sink temperature field distribution cloud map

Figure 8 Cloud diagram of temperature field distribution of new heat sink for low-noise model

3 Experimental verification results

3.1 Noise experimental results (as shown in Table 1)

3.2 Temperature rise test data (as shown in Table 2)

From the temperature rise test results, the temperature rise level of most key components of the low-noise induction cooker is at a low level, which fully meets the quality requirements of the national standard.

Table 1

Table 2

Table 1 Noise realization results

4 Conclusion

Using this program to reduce the noise of induction cooker, the Reduce the noise to about 32dB and achieve low noise The noise effect. The temperature rise of key components is kept at a low level, and ensure the reliability of the product itself reliability, performance stability and reliable quality. This study research solution can be applied to other home appliances to reduce noise pollution to improve the competitiveness of products in the market. competitiveness in the market.

  To achieve the desire goal, two seemingly contradictory difficulties must be solved: (1) the difficulty of noise reduction; (2) and the temperature rise of components. 

The noise problem is a long-standing problem of induction cookers where the fan noise accounts for a large proportion. And how to reduce this part of the noise is a difficult point of the project. The second is the difficulty of heat dissipation. To ensure that the noise is being reduced, the components above the electronic control board must be properly maintainedD