TECHNO-ECONOMIC EVALUATION OF PIPELINE COMPRESSION SYSTEM: EVALUATION OF GAS COMPRESSOR POWER IN A NATURAL GAS PIPELINE NETWORK—PART 1

This paper investigated the proposed 4,180km Trans-Saharan gas pipeline (TSGP) project by the Nigerian government. The main aim of part 1 of this paper was to determine the power requirement of the gas compressor across the entire compression station in a non-isothermal condition with the available data in a time-based system. The gas compressor evaluation takes into account, the ambient temperature, pipeline elevation, required volumetric flowrate, balance piston mass flow and mechanical losses. Also, the effect of the suction pressure of the gas compressors on the power requirement was investigated. Aspen-Hysis was used to validate the gas compressor power evaluation. The results of the study showed that the inlet pressure of the gas compressor reduces as the ambient temperature increases and the increase in the ambient temperature with respect to time of day led to the gas compressor power increase. Further results obtained indicated that the power of the gas compressors for the various compressor station varies from one station to another due to the variation in the polytropic head, which is caused by the varying ambient temperature. Significantly, the investigation revealed that for every 1% rise in the gas temperature resulted in a 3.4% rise in the power required by the gas compressor to move the gas. Finally, the proposed methods in achieving the power requirement of the gas compressors for multiple compression station will help in the prime mover selection, taking into account the impacts of different ambient temperatures and pipeline elevation.