Simulation study on the flow field of guide vane and impeller of turbo expander

Abstract

In the face of the current energy shortage, organic Rankine cycle (ORC) technology is a way to make efficient use of energy, especially geothermal energy. As the core component of an ORC system, a turbo expander can achieve a high conversion efficiency for geothermal energy and has good development prospects. For low temperature geothermal energy such as 95°C water, R245fa could be chosen as the working fluid. Through preliminary thermal calculations and the MATLAB programming method, the main thermal performance parameters and the aerodynamic parameters, structural parameters, and three‐dimensional modeling of the guide vane and impeller were obtained. The design of the turbo expander was modeled and meshed by the Workbench module using the ANSYS software, and the internal flow path of the expander was numerically simulated by the CFX module. The results showed that there was a small range of wake loss at the trailing edge of the vane flow; impact loss and wake loss occurred at the leading and trailing edges of the impeller blades. At the 30% relative chord strength of the impeller, there was excessive expansion, resulting in a local low‐pressure area and a secondary flow from the hub to the rim.

Withdrawn: Flow field analysis of a turbo expander based on organic rankine cycle for geothermal power system simulation

“…The k‐ω model 36 has been revised by the eddy viscosity coefficient μ t and can be expressed as $$${v}_{t}=\frac{k{a}_{1}}{\max ({a}_{1}\omega ,S{F}_{2})},{\mu }_{t}=\rho {v}_{t}.$$$…”

Molecular dynamics simulation on the displacement behaviour of crude oil by CO2/CH4 mixtures on a silica surface

“…The composition of the produced gas mainly includes CO 2 , as well as hydrocarbons (mainly including CH 4 ) and other mixed gases dissolved in the crude oil. 27 In terms of utilizing the produced gas, reinjecting the produced gas as a driving agent back into the oil and gas reservoirs gains popularity, 28 due to reducing resource waste and mitigating environmental pollution. 29,30 During the gas ooding process, the most dominant factor is the interaction mechanism between gas, oil and the reservoir matrix.…”