Comparison of two hybrid systems employing linear Fresnel collector and waste heat recovery based on energy, exergy, economic, and environmental aspects

Abstract

This research aims to develop a new hybrid system that incorporates a linear Fresnel collector (LFC) and waste heat recovery technology using direct storage tanks (DST) to generate stable and uninterruptible power. Moreover, the proposed hybrid system is assessed in terms of energy, exergy, economic, and environmental factors and is compared to a direct steam generation (DSG) hybrid system. In both systems, the heat recovery system recycles the waste heat of an electric arc furnace's low-temperature flue gases. In the first system, the DST plays a vital role in reducing the solar field's fluctuations to provide a stable heat load for an Organic Rankine Cycle (ORC). The ORC receives continuous thermal energy with a solar multiple of 2.7 and a storage capacity of 16 h, generating an average net power of 1,253.80 kW throughout a full day. The findings show that the DST hybrid system has a 10.50% and 14% thermal and exergy efficiency superiority over the DSG hybrid system, respectively. Upon comparing the two hybrid systems, it is evident that the cost of the generated electricity is approximately 25% lower when using two DSTs. However, the DSG hybrid system shows greater savings in both emissions and production costs of CO2.