Estimation of Steam Pipeline Network Heat Losses at the Cerro Prieto Geothermal Field Based on Pipeline Thermal Insulation Conditions

摘要

A study to estimate the magnitude of the heat losses from the Cerro Prieto Geothermal Field (CPGF) steam pipeline network was carried out based on an inventory of the physical condition of the pipeline insulations and field operating data. The heat loss calculations were performed using an iterative method that determines the pipe surface temperature based on a heat balance that takes into account the three basic mechanisms of heat transfer: conduction, convection and thermal radiation. For the inventory, a Geographical Information System was used to map and calculate the pipeline lengths with different insulation conditions and pipe diameters. An MS Excel worksheet-based program was developed to automatically compute the overall heat transfer coefficients according to the operating conditions of the pipeline network and for each thermal insulation condition. Results indicate that the estimated heat loss for the entire CPGF steam pipeline network amounted to 72.9 MWt, which is equivalent to 17.6 MWe of electric power and represents about 2.5% of the current installed capacity.