Experimental investigation of a 50 kW-class R1336mzz(Z) organic Rankine cycle power generation system for waste heat recovery

초록

The organic Rankine cycle (ORC), which uses a fourth-generation refrigerant, has gained increasing attention as a next-generation power generation system for the recovery of waste heat in the low- and medium-temperature range. However, several technical challenges related to the design and operation of the system remain unresolved. In particular, the operation of the turbomachinery in the design stage is critical to demonstrate the feasibility of this technology. In this study, the current status of a 50 kWe R1336mzz(Z) ORC power generation system developed in the Republic of Korea was presented, focusing on the detailed design methodology, system integration, and experimental operation. The cycle layout, based on a simple regenerative configuration, was designed using an in-house code to optimize the 50 kWe pilot plant for waste heat recovery. Detailed designs of the key components, including the turbomachinery and heat exchangers, were then developed, and a pilot plant was constructed as a hermetic system. A power generation test was conducted to verify the design performance of the pilot plant. Stable operation of the ORC system at the design point was successfully achieved with a turbine inlet temperature of 192.75 degrees C, an inlet pressure of 1.75 MPa, a rotational speed of 68,000 rpm, and an expansion ratio of 8.0. The proposed cycle achieved a thermal efficiency of 10.9% at a turbine inlet temperature of 192.75 degrees C, and the pilot plant generated approximately 47.5 kWe of power. This study provides one of the first experimental validations of an ORC system employing the low-GWP refrigerant R1336mzz(Z) at a pilot scale, offering practical design data and operational insights for the development of future industrial waste-heat recovery systems.

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