长时间序列无动力渗透泵流体输运机理研究

Biogeochemical Cycles and Global Climate Environment Evolution are long and slow dynamic processes. Only by long-term high-resolution data of sediment pore water, researchers can analyze the variation features of these processes and obtain the correct results. Under the condition of non-power, penetrating pump can work in seafloor in situ for a long time (at least one year), reliably and autonomously samples sediment pore water with long-time series. In the first-phase research work, penetrating membrane is probably a good way for long term sampling. By combination of theory and experiment, establishing the penetrating pump with membrane as a key part, the research subject will explore the working mechanism of fluid in the pump and in long and thin pipeline. By the results of the resaerch, the correlation of momentum, heat and mass will be established under the condition of different temperature, concentration, velocity and pressure, and the transport mechanism will be charified. Later the transport mechanism will be used to guide the design of the penetrating pump.

海底沉积物间隙水的物理化学特征是研究全球碳循环、古气候变化、生物演化、地层对比等方面不可缺少的技术资料。这些循环过程和演变过程是长期的、缓慢的动态变化过程，就需要有能够进行长期、原位、连续时间序列的海底沉积物间隙水采样技术及其设备。目前大多数间隙水采样技术无法完成这一任务，短期内间隙水的采样只能获得有限数据，难以全面认知这些过程的时空变化特征和变化规律。在前期研究中申请者和海洋地质国家重点实验室发现膜器件可用于间隙水的长期、无动力采样。在此基础上，本课题将采用理论与实验结合的方法，构建以膜器件为核心的渗透泵，应用流体输运理论、流体力学、热力学等，探明流体在渗透泵中的流动规律、探明长而细管道中间隙水的流动机理，获得在不同浓度、温度、速度、压力等条件下，流体的动量、热量、质量等之间关系的输运规律，从而阐明间隙水长期采样的输运机理，为无动力渗透泵的研制提供理论依据。

渗透泵流体输运机理研究是保证渗透泵在无外界动力条件下高质量获得海底沉积物间隙水样本的前提，包括理论分析、数值仿真、试验测试验证、样机设计制造和改型等。渗透泵原理样机由抗压耐腐蚀壳体、渗透膜构件和采样管等核心部件组成。渗透泵采用正渗透原理，重点探索了渗透通量及与温度梯度、浓度梯度、膜性能参数等关键因素之间的相互作用机理，建立了流体分离传质计算模型。通过组分输运模型数值仿真和实验测试，从流速梯度引起的分子移动和分子扩散两个方面建立了间隙水在采样管内流动和扩散的理论模型。本研究获得的长期稳定维持渗透压的流体分离传质计算模型和流体输运机理可作为无动力渗透泵设计的理论依据。