Global Journal of Researches in Engineering, A: Mechanical & Mechanics, Volume 22 Issue 1

Performance of a Capstone Gas Turbine based Power Plant Working on High Butane LPG Carlos Romero α , Yamid Carranza σ & Ricardo Acosta ρ Abstract- In this paper there are presented the results of the operational performance of a 30 kW microturbine generator (MTGs) fed with high butane content liquefied petroleum gas, while subjected to a stand-alone test procedure involving steady and transient load conditions. Neither modifications, nor regulations were made to the micro-turbine system for operation on the liquefied petroleum gas. To evaluate the performance, measurements of turbine and generator parameters were gathered from its original unit controller, as load changes were applied by changing load-bank values. For the stand-alone mode detailed graphs of the test results are presented, showing the transparency and robustness of the turbine-generator set to the used fuel, judging by the quality of the output electric parameters. The results from this performance testing provide good insight into the use of high- butane content liquefied petroleum gas as fuel for the tested microturbine. The continuous use of a fuel would need more tests to establish that the life of the critical components of the microturbine are not hampered from what they are on the baseline fuel. The course of selected performance parameters in the microturbine generator fuelled with LPG is described in this document. The analysis of test results of the microturbine under steady-state and transient operation have been made. Both in steady state and transient conditions, values of output power, speed fluctuation, emissions, noise levels, and exhaust gas temperatures remained under acceptable levels. Keywords: gas turbine, high butane LPG, electrical generator, performance, power generation. I. I ntroducción he need to respond in a safe, efficient and environmentally sustainable manner to the growing energy needs in the different sectors of the national economy, demands the rationalization, technical improvement and expansion of the sources of electricity supply. Responding to this demand, the Colombian Ministry of Mines and Energy, the Unit for the Mining-Energetic Planning (UPME), and the Energy and Gas Regulation Commission (CREG) lead a comprehensive policy that promotes, generates and stimulates programs and projects for the generation, saving and efficient use of energy and particularly for self-generation [1] [2] [4- 9]. The Colombian Government issued Decree 2143 of 2015 [9], through which tax incentives are regulated for the promotion, development and efficient use of energy. The micro-grids find their way, with Author α σ ρ : Universidad Tecnológica de Pereira. e-mail: cromero@utp.edu.co sources of distributed generation, local storage, controlled loads, and the possibility of developing electrical islands. Colombia is promoting programs for distributed generation (DG) and will probably encourage more projects for self-generation in the commercial, residential and service sectors, emulating initiatives as that of the US Department of Energy, which promoted the Advanced Alternative Engine Systems program (ARES), designed to develop small micro-generators units of high efficiency [12]. If incentives are created for self-generation in commercial, residential and service sectors, the incorporation into the system of micro- generation units could be attractive, and the introduction of microturbine generators could be favored. On the other hand, Colombia is currently exporting LPG, a part of which is obtained as a byproduct of natural gas purification in known fields as Cusiana. Some energy suppliers have had interest in exploring the performance behavior of power generators when they are run on high butane liquefied petroleum gas for electricity generation in oil fields. Considering the fact that to date, to the authors’ knowledge, there has not been reported any experimental tests related to the performance of microturbine generator (MTG) sets fuelled with LPG from Cusiana, a 30 kW Capstone MTG fed with Cusiana LPG was tested, as a pilot experience, to judge about its power output, step response, power quality, and fuel consumption. Microturbines are lightweight and compact in size combustion turbines with outputs of 30 kW to 400 kW that can be used for stationary energy generation applications at sites with space limitations for power production. They can be run on natural gas, biogas, propane, butane, diesel, and kerosene. Particularly, the Capstone MTG consists of a compressor, recuperator, combustor, turbine and permanent magnet generator; the air drawn through the inlet system refrigerates the generator, discarding the need of a liquid cooling system. Intake air is compressed and injected into the recuperator, a heat exchanger where it is heated by turbine exhaust. Fuel enters the system through an injection port and is mixed with the heated compressed air. The ignition system causes the air-fuel mixture to burn in the combustion chamber under constant pressure conditions; the resulting gases are allowed to expand through the turbine section to perform work, rotating the turbine blades to turn a generator, which produces electricity. The rotating components, which T Global Journal of Researches in Engineering (A ) Volume XxXII Issue I Version I 17 Year 2022 © 2022 Global Journals