Investigation of an artificial cold source with variable temperature for ORC test rig

Abstract

Organic Rankine cycle (ORC) power generation system is applied to the cascade heat utilization system. The temperature of cold and heat sources has the significant effect on the performance of ORC system. To study this effect efficiently and easily operated, an artificial cold source with variable temperature in the range of -25–35°C was designed for ORC test rig, and an experimental study was conducted. The experiment investigated the effect of outdoor temperature and compressor frequency on the cold source temperature for a heat source output temperature in the range of 50–120°C. An experimental empirical formula for adjusting the cold source temperature independently was established, modified, and experimentally verified. The results demonstrated that the modified formula with two variables exhibited a quadratic polynomial relationship with the correlation coefficient R2 values in the range of 0.9992–0.9995. The verification experiments demonstrated that the calculated value was within ±0.5°C error range from the experimental value. The empirical formula can realize the accurate cold source temperature for ORC test rig. Eventually, the novel artificial cold source with variable temperature test rig can be used to conduct experimental studies on the operational performance of ORC systems under different temperature conditions from subtropical to temperate regions.

Keywords

• Variable cold source temperature
• Low temperature ORC system
• Experimental analysis
• Empirical formula