Proposal and Investigation of a New Tower Solar Collector-Based Trigeneration Energy System

Abstract

These days, the low efficiency of solar-based thermal power plants results in uneconomical performance and high-cost uncompetitive industries compared with conventional fossil fuels. In order to overcome such issues, a novel combined cooling–power–heating (trigeneration) system is proposed and analyzed in this paper. This system uses an ammonia–water binary mixture as a working fluid and a solar heat source to produce diverse types of energy for a multi-unit building in a sustainable fashion. In addition to the basic cooling–power cogeneration cycle, a flashing chamber that will boost the flow rate of refrigerant without any additional heat supply is employed. By developing a mathematical model, the system performance is analyzed using varying parameters of solar irradiation, hot oil temperature, process heat pressure, and ambient temperature to investigate the influence on electrical power, cooling capacity, refrigeration exergy, energy utilization factor (EUF), and system exergy efficiency. Increasing direct normal irradiation (DNI) from 500 W/m2 to 1000 W/m2 reduces the system EUF and exergy efficiency from 53.62% to 43.12% and from 49.02% to 25.65%, respectively. Both power and refrigeration exergy increase with increasing DNI and ambient temperature, while heating exergy remains constant. It is demonstrated that of 100% solar energy supplied, 46.03% is converted into energetic output and 53.97% is recorded as energy loss. The solar exergy supplied is distributed into 8.34% produced exergy, 29.78% exergy loss, and the remaining 61.88% is the destructed exergy. The highest destruction of solar exergy (56.89%) occurs in the central receiver.