HIGH EFFICIENCY MHD POWER GENERATION WITHOUT USING ALKALIMETAL

通过使用闭合循环磁流体动力（MHD）发电的概念，可以实现高效率发电。我们一直建议使用氙作为种子材料，而不是碱金属，这会产生不良的环境影响，并降低系统的可靠性。到目前为止，作为发生器设计和操作条件的优化的结果，虽然氦/氙工作气体可以提供如用常规碱金属种子获得的显著高的发生器性能，但是重要的是将等离子体保持在稳定的条件下以实现高性能。其次，我们利用二维数值模拟的方法研究了等离子体稳定性与发生器性能的关系。已经阐明，氦/氙等离子体本质上是不稳定和不均匀的。这种不稳定性导致气体速度的强烈降低和气体压力的增加，这导致发生器性能的显著退化。然而，如果我们选择发生器的设计和操作条件，以防止这种不利的影响，即使等离子体是不稳定的和不均匀的，性能成功地恢复到高值获得稳定的等离子体使用碱金属种子。上述结果通过这个科学项目获得了许多国际和国内会议和研讨会。作为闭式循环磁流体动力学的新进展，我们得到了令人鼓舞的讨论和评论，并建议我们继续对现有的氦/氙工质概念进行实验验证。我们确实有一个计划来沿着这个建议前进。

High efficiency electrical power generation can be possible by using the concept of closed cycle magnetohydrodynamic (MHD) electrical power generation. We have been proposing to use xenon as seed material Instead of alkali metal, which gives rise to bad environmental influence and to reduction of system reliability. So far, as a result of optimization of generator design and operating conditions) although helium/xenon working gas can provide significantly high generator performance as is obtained with conventional alkali metal seed, it is important to keep plasma in a stable condition in order to achieve high performance. Next, we have been studying the relation of plasma stability and generator performance by means of 2-dimansional numerical simulation. It has been clarified that helium/xenon plasma is inherently unstable and non-uniform. This instability produces strong decrease in gas velocity and increase in gas pressure, which result in significant degradation of generator performance. However, if we choose generator design and operating conditions so as to prevent from such unfavorable effects even if the plasma is unstable and non-uniform, performance successfully recovers to high value as obtained with stable plasma using alkali metal seed.Above results obtained by this scientific project have been presented many international and domestic conferences and symposiums. We receive encouraging discussions and comments as new movement in closed cycle MHD.We also are suggested to continue to perform experimental demonstration of the present concept of helium/xenon working medium. We do have a plan to move on along this suggestion.