Session: 4.1.4 - Renewable Energy Systems

Paper Number: 110208

110208 - Proposal and Investigation of a New Tower Solar Collector Based Trigeneration Energy System 

Investigations encountered in the literature on the development and assessment of combined energy systems comprising of a Kalina cycle and an absorption chiller integrated into solar energy source reveal a low performance of absorption refrigeration cycle due because a significant amount of energy input is required to attain the separation process. The introduction of a flash chamber in the previously investigated cogeneration cycles assists in producing the additional refrigerant without a further supply of any heat by flashing which leads to a greater output of cooling and power. Exergy analysis of such modified combined energy systems can provide further insights. Few researches on the integration of the parabolic trough solar collector system with the Kalina cycle and absorption cooling cycle with a maximum of two concentration ratios (without flashing) are available. Still, to date, no study reports the development and analysis of the integration of solar tower collector, binary mixture operated combined power, and cooling cycle employing a flash chamber along with the separator. Therefore, the present research aims to present thermodynamic modeling and the exergy analysis of a solar-based trigeneration system. The sub-objectives follow:

·         To model a new trigeneration system based on a tower solar collector, a process heat exchanger, and a cogeneration cycle employing the concept of separation and flashing for the simultaneous generation of heating, power, and predominantly high cooling output.

·         To perform exergy analysis of the system and parametric investigation of the effects of varying selected operating parameters on overall energy and exergy efficiencies.

·         To quantify the distribution of irreversibilities in system components with the aim to identify the weak spot means the component accounts for the highest exergy loss whose reduction helps to improve the system performance.

This communication reports the implementation of solar energy for the new design of a cooling-heating-power trigeneration system utilizing an ammonia-water mixture as a working fluid. In the bottoming part, a flashing chamber is employed to enhance the flow rate of refrigerant without any further supply of thermal energy. By developing a mathematical model, the system performance is analyzed at varying parameters of solar irradiations, hot oil temperature, process heat pressure, and the ambient temperature to investigate the influence on electrical power, cooling capacity, refrigeration exergy, energy utilization factor (EUF) and the system exergy efficiency. Increasing DNI from 500 W/m 2 to 1000 W/m 2 declines 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 increases with the increase in DNI and ambient temperature while the heating exergy keeps constant. Overall system performance demonstrates that supplied solar energy is transformed into 46.03% energetic output and 53.97% energy losses. The solar exergy is distributed as 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%) is obtained in the central receiver.

Presenting Author: Eydhah Almatrafi King Abdulaziz University

Presenting Author Biography: Dr. Eydhah Almatrafi is an associate professor in the Mechanical Engineering Department Rabigh at King Abdulaziz University (KAU), Jeddah, KSA. His primary area of research is centered on the development of innovative methods to integrate water desalination technologies with renewable energy resources. In his Ph.D., he developed novel solar-powered desalination systems for small-scale desalination applications.