Testing of a 40-kWth Counterflow Particle-Supercritical Carbon Dioxide Narrow-Channel, Fluidized Bed Heat Exchanger

Conference · Mon Feb 19 04:00:00 EST 2024 · SolarPACES Conference Proceedings

DOI:https://doi.org/10.52825/solarpaces.v1i.634· OSTI ID:2428973

Arthur-Arhin, Winfred; Fosheim, Jesse R.; Brewster, Keaton J.; Thompson, Azariah; Albrecht, Kevin J.; Amogne, Dereje; Jackson, Gregory S.

Particle-based primary heat exchangers (HXs) must deliver sCO2 fluid temperatures above 700°C to couple particle-based concentrating solar receivers and thermal energy storage (TES) sub-systems with efficient sCO2 power cycles. Particle-sCO2 HX designs have struggled to meet DOE cost targets (≤ $150/kWth) due to the amount of expensive nickel alloys necessary for manufacturing full-scale, particle-sCO2 HXs. Our team has demonstrated that mild bubbling fluidization of falling particles in a counterflow narrow-channel fluidized bed can reduce required HX surface area and thus, costs by increasing particle-wall heat transfer coefficients hT,w > 800 W m-2 K-1. This paper reports on the fabrication and testing of a stainless steel, particle-sCO2 HX with 12 fluidized-bed channels approximately 10.5 mm deep spaced between diffusion-bonded, micro-channel sCO2 plates. The HX with a core length of ≈0.56 m is fed with CARBOBEAD HSP particles through a short, fluidized freeboard zone just above the core. Testing to date in the National Solar Thermal Test Facility (NSTTF) at Sandia National Laboratories has shown that parallel bed fluidization maintains uniform particle inventory across the instrumented channels. Heat transfer thermal duty between the particle and sCO2 flows exceeds 30 kWth with sCO2 inlet temperatures of 200ºC and particle inlet temperatures up to 440ºC and mass flow rates of 0.2 kg s-1 fluidized by counterflowing gas flow rates of 0.005 kg s-1. Tests at higher particle and sCO2 inlet temperatures (600ºC and 400ºC respectively) are targeted to achieve > 40 kWth with model-predicted overall heat transfer coefficients U > 400 W m-2 K-1.

• Research Organization: Colorado School of Mines
• Sponsoring Organization: USDOE Office of Energy Efficiency and Renewable Energy (EERE), Renewable Power Office. Solar Energy Technologies Office
• Contributing Organization: Sandia National Laboratory Vacuum Process Engineering
• DOE Contract Number: EE0008538
• OSTI ID: 2428973
• Conference Information: Journal Name: SolarPACES Conference Proceedings
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
Particle Heat Exchanger
Fluidized Bed
Supercritical CO2
Thermal Energy Storage