Proposta de solução para optimização do sistema de protecção e accionamento de um compressor de ar no centro fabril da Mozal - Matola

Abstract

Mozal is an industrial unit with a high-power installation, approximately 950 MW, where the majority of the consumed energy is used in the electrolytic process to feed the pots. In this phase, aluminum oxide (AlO3) is reduced to aluminum (Al). The process involves automatic machines called Pot Tending Assembly (PTAs), which rely on electric machines to operate the air compressor. However, like any engineering system, the compressor has vulnerable points that compromise its performance and have negative impacts on the company. The issue studied in this work pertains to the current protection and activation system of the compressor, specifically the frequent discharges and unscheduled energy interruptions. This work was developed at Mozal, an aluminum factory located in Beluluana, as an internship report to be presented at the Faculty of Engineering of UEM. The objective is to propose solutions to overcome current challenges in the maintenance of PTAs and optimize the air compressor’s performance. The work includes a literature review that supports the subject under study, based on various consulted sources. To address the formulated hypotheses, data from seven months of compressor performance were collected, followed by critical and statistical analysis. Based on the analysis results, solutions were devised and detailed. The proposed solutions focus on optimizing the compressor, with a specific focus on eliminating vulnerabilities in the main compressor circuit breaker and ensuring conditions that sustain its functionality. Therefore, these solutions aim to surpass current challenges and genuinely optimize the compressor’s performance. Additionally, the proposed solutions are cost-effective compared to the losses caused by unscheduled compressor shutdowns, making the project viable.