Research Article

Modelling of A Solar Thermal Energy System For Energy Efficiency Improvement In A Ceramic Plant

Low Carbon & Resource Efficiency, R&D, Instituto de Soldadura e Qualidade, Portugal

^* e-mail: dmoliveira@isq.pt; mciten@isq.pt

Received: 3 July 2021
Received in final form: 16 August 2021
Accepted: 17 August 2021

Abstract

The thermal energy use in the manufacturing plants is the most representative parcel of the total energy consumption within the European industry. Such is mainly attributed to the operation of high energy intensive thermal processes such as furnaces and boilers. The implementation of heat recovery technologies is a solution with a great potential to improve the operation of these processes and improve the overall energy efficiency in a plant. On the other hand, the use of renewable energy resources such as solar energy is highly relevant measure to decrease the use of fossil fuels, such as natural gas. This paper presents the modelling of a solar thermal energy system (STES) established by a water circuit and solar thermal collector for the heat supply to two boilers installed in a ceramic plant. Such system has been conceptualised in the scope of industrial practices, proposing solar heat for industrial processes (SHIP). The practical work in this paper aims to the development of a customised simulation tool for the modelling of heat recovery networks and thermal processes in manufacturing industry plants using the Modelica language. The system model has been developed using existing and newly developed equipment models. The simulation results were validated with measured data in the industrial plant, being consistent with the real values (e.g. highest deviation of about 0.01%). In addition to the boilers, the performed simulation allowed to achieve the sizing of the components of the water circuit, in particular for the pumping system (with a required supply of 0.747 kW of electric energy). A techno-economic assessment has been performed to evaluate the viability of the cproposed solution, showing a payback time of approximately 3 years, a total annual economic savings of about 25209 € and associated reduction of equivalent carbon dioxide emissions of about 170 ton/year.