Performance assessment of a system to provide steady high temperature air via solar thermal suspension flow technology with storage and combustion back-up

Abstract

The imperative for economically viable sources of high-temperature heat without contributing to net carbon emissions has become a pressing global concern, particularly in the context of industrial chemical processes. Solar thermal heat generation emerges as a pivotal solution in addressing this formidable challenge. By concentrating sunlight to achieve high temperatures, solar thermal technology can provide the intense heat required for various industrial applications, including chemical processes, without relying on fossil fuels. This not only helps reduce greenhouse gas emissions but also enhances energy efficiency and sustainability in energy-intensive industries. However, the full integration of solar thermal systems into energy-intensive industrial processes necessitates continued advancements of new technologies to achieve temperatures in the order of 1000 °C. In this paper, the performance of a high temperature concentrating solar thermal plant based on a 50MWth suspension flow solar particle receiver sub-system integrated with sensible thermal storage and combustion backup is analyzed, to supply steady output of reheated air to a downstream thermochemical process. The analysis is performed with transient mathematical models of the receiver and packed bed thermal storage sub-systems considering solar resource variability, written in a Simulink environment, to estimate useful annual thermal gain, thermal efficiency, solar share and levelized cost of solar heat, for a range of parameters including particle mass loading, air mass flow rate, thermal storage capacity and solar multiple. The time-dependent temperature fields of the receiver and thermal losses, together with their influence on the performance of the combined system are reported for each condition with a transient input solar resource spanning over a whole year. New insights are provided of the relative tradeoffs between these parameters on the overall system performance, solar share and levelized cost of solar energy. Also reported is the sensitivity of the levelized cost to different system combinations sized to provide a solar share of up to 75 % of the yearly process thermal demand, along with the influence of the specific costs of the system components varied in the range of ± 60 %.