为了克服采用传统机械方法开采海底富钴结壳时破碎头易磨损、效率低以及贫化率高等缺点, 通过试验方法研究了一种利用脉冲功率技术开采海底富钴结壳的新技术。采用12级全固态Marx电路和半导体开关IGBT研制了高压脉冲电源, 该电源可产生负高压方波脉冲, 其上升沿上升时间约100 ns, 最高幅值可达40 kV, 脉宽可调。破碎方式采用针针电极并与岩石同侧表面紧密接触。为了使两电极与岩石同侧表面接触的部位电势尽可能高, 采用不锈钢针作为正、负电极, 且电极间距可调。研究发现当电极间距约为3 mm时, 该电源产生的幅值约32.5 kV的高压脉冲可在高压油中的砂岩内部形成等离子通道并破碎砂岩。放电既可发生在高压脉冲上升沿阶段, 也可发生在上升沿上升时间之后。从放电过程中的电压电流波形来看, 等离子通道回路中有电流时其两端存在明显的压降, 因此等离子通道具有阻性, 而且阻值在放电过程中是变化的。

In order to overcome the disadvantages of using the conventional mechanical methods to explore marine Co-rich crust, such as crushing head wearing easily, low efficiency and high dilution ratio, we developed a new technology using experimental investigation, in which the pulse power techniques were used to explore the marine Co-rich crust. A power source was designed using solid-state Marx circuits together with semiconductor switch IGBT, which could generate negative high voltage pulses with rising edge 100 ns and maximum amplitude 40 kV. The breaking way adopted needle-needle electrodes which contact the same surface of rocks closely. To improve the potential of areas where the needles contact with the surface of rocks, stainless pins were used as the electrodes. Results indicate that plasma channels were generated and sandstones were broken when the amplitude of high voltage pulse was 32.5 kV and the distance between electrodes was 3 mm. Moreover, discharges happen either during the rising-time or after the rising-time of high voltage pulses. The changing curves of voltage and current show the plasma channels have variable impedance during discharge processes.