Abstract

Utilization of spray ejector condenser in order to carry out direct-contact condensation of vapour with inert gas (CO2) on a spray of subcooled liquid integrated with separator (to make pure CO2) has been proposed for the task of condensation and CO2 separation in the negative CO2 emission gas power plant. Condensation and separation has a significant impact on the thermodynamic efficiency of the entire negative CO2 emission gas power plant cycle. The study presents the accomplished analysis using the numerical model of cyclone separator cases with varying spray ejector condenser outlet conditions. The model incorporates the continuity and momentum equations to describe the phenomenon of separation. Here, transient, turbulent and three-dimensional separator is numerically modelled based on a control volume method in Fluent. The Reynolds Stress Model is also derived from Reynolds Averaged Navier-Stokes's solution. This model is adopted to numerically simulate turbulent flow in separators. In addition, the mixture model is applied for simulation of turbulent swirl two-phase flow in gas-liquid separator. To obtain a numerical model and optimize the purification of CO2, firstly, different length of cone of cyclone separator should be investigated. Then, the numerical simulation on different value of volume fraction of two phase flow is conducted, and by applying 10% up to 20% of volume fraction for water liquid, the model is derived. Results show that as the liquid volume fraction decreases, the separation efficiency improves. The most optimal separation efficiency of 90.7% is achieved when the liquid volume fraction is at 10%. In addition, Increasing the length of the cone results in both higher efficiency and pressure drop. Specifically, when the length of the cone is increased from 128 mm to 528 mm, the efficiency and pressure drop increases by 4.2% and 194.14 (pa), respectively.

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Authors (4)