微小通道内多组分生物质甲烷冷凝传热特性与多元两相流动行为的研究

It is the key to enhance the condensation heat transfer process for reducing energy consumption and increasing conversion efficiency in skid-mounted biomass methane liquefaction system. Fundamental research on condensation heat transfer and two-phase flow performance, thermodynamics phase-change process and mechanism for multi-component biomass methane in mini/micro channels is conducted. The specific content includes: The effects of physical properties , inlet temperature, flow rate, pressure of biomass methane on condensation heat transfer coefficient, pressure drop and the energy consumption in mini/micro will be studied through the basic test and theory analysis combined with numerical simulation; the biomass methane condensation heat transfer prediction model will be built. The formation, development and evolution of gas-liquid interface in condensation process under coupling of multi-component and two-phase will be obtained. The correlation between the property, gas-liquid density and condensation heat transfer coefficient will be revealed. The results in this project are expected to break the bottleneck of biomass resources efficient conversion, which will provide the theoretical reference for skid-mounted biomass methane liquefaction system in large-scale commercial application.

强化冷凝相变传热过程是降低小型撬装生物质甲烷液化装置系统能耗，提高转化效率的关键。项目对多组分生物质甲烷在微小通道中冷凝传热流动性能和热力学相变过程与机理展开基础研究。具体内容包括： 通过基础实验、理论分析结合数值计算的方法，探索生物质甲烷物性、进口温度、流量、压力等关键参数对微小通道冷凝传热系数、压降与系统能耗的影响规律，建立生物质甲烷冷凝传热预测模型；获得多元两相耦合作用下生物质甲烷冷凝过程中气-液两相界面的形成、发展与演变过程，揭示介质物性、气液相密度与冷凝传热系数之间的关联规律。项目研究有望突破生物质资源高效转化的瓶颈，为实现小型撬装式生物质甲烷液化装置大规模商业化应用提供可借鉴的理论。

强化冷凝相变传热过程是降低小型撬装生物质甲烷液化装置系统能耗，提高转化效率的关键。本项目通过开展微小通道流动与传热性能实验，探索微尺度下强化传热结构，获得了介质在不同进口温度、速度下3种截面形状、3种端口数量、2种异型微肋微小通道的冷凝传热系数与压降。结果表明：在相同工况下，三角形截面微小通道的传热系数与压降最大，矩形次之，半圆形截面微小通道最小；平均传热系数与压降随通道数的增加而增大，端口效应明显；对比矩形微小通道，单边微肋异形微小通道综合传热性能更好，强化传热效果显著。.基于微尺度与传热多相耦合特性，建立了微小通道三维数值模型，完成了气液两相界面的动态变化过程的非稳态数值计算，获得了甲烷在微小通道中气-液界面演变过程；研究了介质进口温度与速度、水力直径对微小通道冷凝传热与流动性能的影响，对比分析了多端口微小通道两相流动行为，探索端口数量对冷凝相变流动行为的影响，优化异形微小通道结构。项目研究成果为实现小型撬装式生物质甲烷液化装置大规模商业化应用提供理论参考。