Digital Twins of the Water Cooling System in a Power Plant Based on Fuzzy Logic.

Carlos Antonio Alves De Araujo Junior,Isaac Emmanuel Azevedo De Medeiros,Rodrigo José Silva De Almeida,Juan Moises Mauricio Villanueva

doi:10.3390/s21206737

Carlos Antonio Alves De Araujo Junior, Isaac Emmanuel Azevedo De Medeiros + Show 2 more

Open Access

https://doi.org/10.3390/s21206737

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Abstract

In the search for increased productivity and efficiency in the industrial sector, a new industrial revolution, called Industry 4.0, was promoted. In the electric sector, power plants seek to adapt these new concepts to optimize electric power generation processes, as well as to reduce operating costs and unscheduled downtime intervals. In these plants, PID control strategies are commonly used in water cooling systems, which use fans to perform the thermal exchange between water and the ambient air. However, as the nonlinearities of these systems affect the performance of the drivers, sometimes a greater number of fans than necessary are activated to ensure water temperature control which, consequently, increases energy expenditure. In this work, our objective is to develop digital twins for a water cooling system with auxiliary equipment, in terms of the decision making of the operator, to determine the correct number of fans. This model was developed based on the algorithm of automatic extraction of fuzzy rules, derived from the SCADA of a power plant located in the capital of Paraíba, Brazil. The digital twins can update the fuzzy rules in the case of new events, such as steady-state operation, starting and stopping ramps, and instability. The results from experimental tests using data from 11 h of plant operations demonstrate the robustness of the proposed digital twin model. Furthermore, in all scenarios, the average percentage error was less than 5% and the average absolute temperature error was below 3 °C.

Highlights

Brazil has diversified energy generation, mainly organized into hydroelectric, solar, wind, biomass, and thermoelectric plants
We considered three different scenarios: (a) performance of the digital twin operating during the permanent process regime; (b) performance of the digital twin during transients in the process, and (c) digital twin performance during large transients, due to system control failure
The training database was obtained from equipment installed in an internal combustion thermoelectric plant with the following specifications: hot water cooling system with 55 fans operated remotely, automatically, or manually, and five motor-generating units composed of MAN/STX 18V32/40 engines + 10MVA Hyundai generators

Summary

Introduction

Brazil has diversified energy generation, mainly organized into hydroelectric, solar, wind, biomass, and thermoelectric plants. The specific consumption measure—the ratio between power and kilograms of fuel—is an indicator of thermal efficiency, but there is another important measure that will be addressed in this work: the energy consumption of auxiliary equipment [2]. This equipment plays the function of ensuring that the parameters of the main devices (e.g., boilers, engines, generators, and turbines) responsible for the production of energy are controlled and, consume electricity from the production itself to maintain its operation [3]

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