Design of steam gethering system for Menengai Geothermal Field, Kenya

Abstract

Utilizing high temperature geothermal resources for power generation requires design of steam gathering system to transport geothermal fluids. The aim of this project is develop a model that can be used to optimize the steam gathering and the re-injection systems in Menengai geothermal field. The objective function includes the capital investment and the operational cost. The constraints are the steam and water velocity and the upward slope of the two phase flow pipelines. To test the model, different scenarios are analyzed considering different location of the power plants, the separators and the re-injection system. For each scenario the variable topography distance transform is used to locate the separators and find the pipeline route. Topology design optimizes the pipe network and flow in each pipe. The geothermal area is represented by digital elevation matrix (DEM) that is a digital file consisting of the terrain elevations for ground positions at regularly spaced horizontal intervals. Variable topography distance transform (VTDT) is based on chamfer metric distance transform algorithm where the height points from the DEM is incorporated in such way that the heights are assigned to each cell. Developed model is used to size basic components of steam gathering system using Menengai geothermal field data