Studies on Magnetic Induction Heating Equipments to Generate Super-Steam.

制备了三种类型的高频逆变器以产生超蒸汽，其分别在100、200和300 kHz下操作。电路结构采用零电流开关（ZCS）的电压反馈全桥式，开关器件分别为100和200 kHz的静电感应晶体管（SIT）和300 kHz的功率MOS场效应管（MOSFET）。逆变器的设计最大输入功率为6.4 kW（400 V/16 A）。在200 V的输入电压下操作所制备的试验板。用于产生超蒸汽的负载是由Teflon树脂制成的管（外径120 mm，内径100 mm，长度400 mm），其包含加热物质。这是因为聚四氟乙烯树脂易于加工。首先，采用碳陶瓷和磁性不锈钢作为加热物质。然而，我们的初步实验表明，碳陶瓷被发现适合于加热物质。 ...更多信息 e由于其作为热负荷的稳定性。碳陶瓷是直径90 mm、高90 mm的圆柱体。在其上钻14个直径为10 mm的孔，以增加其与流过其中的流体的接触表面。超蒸汽在170 ℃以上是活跃的，但在我们的实验中，它的最高温度被限制在260 ℃以下。考虑到聚四氟乙烯树脂的耐热温度为300 ℃，采用SIT的100和200 kHz高频逆变器尽管波形有些畸变，但仍能稳定工作。另一方面，使用功率MOSFET的300 kHz逆变器显示其波形中的大量失真。因此，它的电路结构和驱动电路应加以改进。在我们的实验中，将800 cc的水注入到特氟隆管中，使得整个底部碳陶瓷浸没在水中。然后，将水加热至98 ° C。最后，继续加热过程，直到另外两种碳陶瓷的温度达到260 ℃。结果，检测到产生透明的超蒸汽。此外，根据实验结果，通过仿真分析，给出了输出功率为50 kW的100、200和300 kHz超蒸汽发生器高频逆变器的具体设计方法，并给出了带辅助开关的SEPP谐振高频逆变器的工作原理和实验结果，为感应加热应用提供了参考。但由于输出功率不足，无法产生超级蒸汽。少

Three types of high frequency inverters were prepared to generate super-steam, which operate at 100, 200 and 300 kHz, respectively. The circuit constitution adopted was the voltage-fed full bridge type operated at zero current switching operation (ZCS).Switching devices utilized were Static Induction Transistors (SITs) for the 100 and 200 kHz inverters and power MOS FET for the 300 kHz inverter, respectively. The inverters were designed at maximum input power of 6.4 kW (400V/16A). The prepared breadboards were operated at input voltage of 200 V. The load for super-steam generation was the pipe made of Teflon resin (outer diameter of 120 mm, inner diameter of 100 mm and length of 400 mm), which contained a heating substance. It came from the reason that Teflon resin was easy to process. At first, carbon ceramics and magnetic stainless steel were adopted as the heating substance. However, our preliminary experiment revealed that carbon ceramics was found suitable for the heating substanc … More e due to its stability as the heating load. The carbon ceramics was a cylinder of 90 mm in diameter and 90 mm in height. The 14 holes of 10 mm in diameter were bored in it to increase its contact surfaces with a fluid flowing through it. Three carbon ceramics were inserted into the Teflon pipe in vertical direction with 15 mm gaps. Super-steam was known active above 170 ℃, however, its maximum temperature was restricted below 260 ℃ in our experiments. It took into account the fact that the heat-resistive temperature of Teflon resin was 300 ℃.The high frequency inverters of 100 and 200 kHz using SITs could be operated stably in spite of some distortion in their waveforms. On the other hand, the inverter of 300 kHz using power MOSFETs revealed substantial distortion in its waveforms. Accordingly, its circuit constitution and driving circuits should be refined. In our experiments, water of 800 cc was inserted into the Teflon pipe so that whole of the bottom carbon ceramics was submerged in water. Then, the water was heated till 98 ℃. Finally, heating process was continued till the temperature of the other two carbon ceramics reached 260 ℃. As a result, transparent super-steam was detected to generate. In addition, simulation analysis revealed the definite design procedure for high frequency inverters of 100, 200 and 300 kHz of super-steam generation feeding output power of 50 kW on the basis of our experimental results.Moreover, operational principle and experimental results of an SEPP resonant high frequency inverter with auxiliary switches operating at high efficiency were found useful for induction heating uses. However, super-steam could not be generated by it since its output power was insufficient. Less