Energy, Exergy and Performance Analysis of Small-Scale Organic Rankine Cycle Systems for Electrical Power Generation Applicable in Rural Areas of Developing Countries

Abstract

This paper introduces the concept of installing a small-scale organic Rankine cycle system for the generation of electricity in remote areas of developing countries. The Organic Rankine Cycle Systems (ORC) system uses a commercial magnetically-coupled scroll expander, plate type heat exchangers and plunger type working fluid feed pump. The heat source for the ORC system can be solar energy. A series of laboratory tests were conducted to confirm the cycle efficiency and expander power output of the system. Using the actual system data, the exergy destruction on the system components and exergy efficiency were assessed. Furthermore, the results of the variations of system energy and exergy efficiencies with different operating parameters, such as the evaporating and condensing pressures, degree of superheating, dead state temperature, expander inlet temperature and pressure ratio were illustrated. The system exhibited acceptable operational characteristics with good performance under a wide range of conditions. A heat source temperature of 121 °C is expected to deliver a power output of approximately 1.4 kW. In addition, the system cost analysis and financing mechanisms for the installation of the ORC system were discussed.

Experimental testing of a low-temperature organic Rankine cycle (ORC) engine coupled with concentrating PV/thermal collectors: Laboratory and field tests

“…Exergetic efficiency is recommended for evaluation of lowtemperature power systems and comparison of their performance for different heat source temperature [38,39]. Exergetic efficiency expression depends on the heat source type and the application [40].…”

Experimental and Thermoeconomic Analysis of Small-Scale Solar Organic Rankine Cycle (SORC) System

“…Kane et al [12] design a mini-hybrid solar power plant integrating solar collectors, ORC cycles and bio-diesel engine to confirm the operational characteristics of this hybrid system to meet the electricity, cooling and pumping needs for rural areas. Baral et al [13] tested a small-scale ORC unit with a commercial scroll expander and found that the unit has the capacity to produce 1.4 kW of electric power when the heat source was 120 °C. In a similar manner, Delgado and Lourdes [14] conducted a parametric study of the influence of the configuration of the solar ORC system for various working fluids in a desalination process to determine the minimum aperture area required to produce mechanical power output under different operating conditions.…”

Thermodynamic analysis and comparison between CO 2 transcritical power cycles and R245fa organic Rankine cycles for low grade heat to power energy conversion

“…To achieve these, exergetic analysis based on the second law of thermodynamics is required [24][25][26]. The exergetic analysis is necessary to understand the extent of irreversibility in each component process, identify…”