Proceedings of the 27th National and 5th International ISHMT-ASTFE Heat and Mass Transfer Conference December 14-17, 2023, IIT Patna, Patna-801106, Bihar, India
Maximum Power Operation Of A Supercritical Carbon Dioxide Simple Recuperated Brayton Power Block
摘要
Supercritical Carbon Dioxide (sCO2) is gaining attention as a promising option for efficient and low-carbon-footprint power generation. These compact systems are particularly wellsuited for arid regions due to the feasibility of dry-cooled operation. This study investigates the design of sCO2 Brayton cycles for peak-power generation applications, focusing on a 5 megawatt (MW) simple recuperated plant with fixed heat exchanger conductance. The maximum power capacity of the plant was analyzed by varying the flow rate of the working fluid within the cycle. The effects of this variation on heat exchanger performance were examined. Notably, it was observed that the cycle's power peaks at reduced efficiency and increased heat duties, resulting in the thermodynamic cycle shrinking on the Temperature-Entropy plane.
The study highlights the significance of heat exchanger pinches and channel flow rates as key parameters for design optimization. To identify the best design, a design pool was generated by varying these parameters around their baseline values. The plant size and cycle efficiency were weighed relative to their best values from the pool. During the optimization process, a trade-off between plant size and cycle efficiency was carried out minimizing the overall cost of electricity.
For the peak load plant, the optimized design achieved a cycle efficiency of 32.5%for heat exchanger pinches and channel flow rates of 10°C and 1.2 g/s, respectively. In contrast, the baseload plant design yielded a 34.8% efficiency at 5°C pinch and 1 g/s heat exchanger channel flow rate.
This methodology offers valuable insights into the design of sCO2 Brayton plants for peak-power generation. It allows for efficient optimization while considering factors like plant size and cycle efficiency. The optimized design not only enhances performance but also contributes to reducing the overall cost of electricity. This approach can be adapted for design under budget or size constraints, making it a versatile design tool.
The study highlights the significance of heat exchanger pinches and channel flow rates as key parameters for design optimization. To identify the best design, a design pool was generated by varying these parameters around their baseline values. The plant size and cycle efficiency were weighed relative to their best values from the pool. During the optimization process, a trade-off between plant size and cycle efficiency was carried out minimizing the overall cost of electricity.
For the peak load plant, the optimized design achieved a cycle efficiency of 32.5%for heat exchanger pinches and channel flow rates of 10°C and 1.2 g/s, respectively. In contrast, the baseload plant design yielded a 34.8% efficiency at 5°C pinch and 1 g/s heat exchanger channel flow rate.
This methodology offers valuable insights into the design of sCO2 Brayton plants for peak-power generation. It allows for efficient optimization while considering factors like plant size and cycle efficiency. The optimized design not only enhances performance but also contributes to reducing the overall cost of electricity. This approach can be adapted for design under budget or size constraints, making it a versatile design tool.