Performance analysis and optimization design of an axial-flow vane separator for supercritical CO₂ (sCO₂ )-water mixtures from geothermal reservoirs

Abstract

Summary Supercritical CO2 (sCO2) has been proven to be a promising working fluid for geothermal heat mining, and the produced hot sCO2 can be directly used for power generation. However, the sCO2 produced from a brine‐based reservoir may contain a certain amount of water, preventing direct power‐cycle utilization. In this paper, an axial vane separator was designed to address the separation problem of sCO2 and water produced from geothermal reservoirs. First, the influences of operational and structural parameters on the separation performance were analyzed through numerical simulations. Five factors were selected to develop separation performance regression models by the response‐surface method (RSM). Finally, geometrical parameter optimization was applied to these RSM models. The results show that the guide vane area and the exhaust inlet are the main locations impacting the system pressure drop. The separation performance can be affected by many factors, including the guide blade outlet angle, number of vanes, hub diameter, length of the vortex tube, droplet size, and inlet velocity. The water‐droplet size and the number of vanes are the most critical factors affecting the separation efficiency. The inlet velocity, the number of vanes, and the hub diameter have a larger influence on the pressure drop of the separator. The optimization results indicate that the separation efficiency can reach 100% under certain operating conditions with a pressure drop no greater than 100 kPa.

Numerical Simulation of Membrane Separation Characteristics of Supercritical Carbon Dioxide and Water

“…The operating characteristics of these separators are analyzed. The results show Authors have researched separation mechanisms for the scCO2-H2O mixture in published studies [4,5]. The principles of gravitational and centrifugal force are used to design the axial guide vane cyclone separator and the biconical hydrocyclone.…”

On the Influencing Mechanism of Geothermal Fluids on the Dynamic Changes of Groundwater Flow and Heat Transfer Temperature

“…Shulyupin et al [19] took a regional groundwater heat pump system project as an example and simulated and analyzed the coupled groundwater flow-heat transfer process under specific heat source conditions. Based on the basic principle of groundwater heat transfer, Qiao et al [20] analyzed the coupling effect of aquifer flow transfixion and heat transfixion and constructed a numerical simulation model for groundwater flow field and temperature field, and also gave the basis for flow transfixion of groundwater flow when the hydraulic slope is neglected. Ovando-Chacon et al [21] performed a case analysis of a regional groundwater heat pump system project, and analyzed and evaluated the simulation results of the coupled groundwater flow-heat transfer process under different influencing factors and the sustainable operation schemes.…”

Design of power‐blocks for medium‐scale supercritical carbon dioxide plants

“…Primarily proposed in conjunction with nuclear power reactors 11 and for the concentrated solar power generation, 12,13 it has also shown promise for use with combined cycle power plants, 14,15 with fuel cells 16,17 and geothermal power. 18 In addition, this application of the S-CO 2 technology has potential value in the marine propulsion sector. 19 In a S-CO 2 cycle the working fluid is compressed (or pumped) up to the maximum pressure and heated to the maximum temperature in a heat exchanger (Waste Heat Recovery Unit).…”

“…In this case, the S‐CO 2 technology can be coupled with a variety of heat sources. Primarily proposed in conjunction with nuclear power reactors 11 and for the concentrated solar power generation, 12,13 it has also shown promise for use with combined cycle power plants, 14,15 with fuel cells 16,17 and geothermal power 18 . In addition, this application of the S‐CO 2 technology has potential value in the marine propulsion sector 19 …”