Plate-style recuperator for a solar Brayton cycle using high-temperature sealant. (August 2020)

• Record Type: Journal Article
• Authors: Dellar, Kyle E.; le Roux, Willem G.; Meyer, Josua P.
• Is Part Of: Applied thermal engineering. Volume 177(2020)
• Publication Date: 2020-08
• Subjects: Recuperator -- Sodium silicate -- Sealant -- Counterflow -- Plate-type -- Brayton; Heat engineering -- Periodicals; Heating -- Equipment and supplies -- Periodicals; Periodicals; 621.40205
• DOI: 10.1016/j.applthermaleng.2020.115439
• Languages: English
• ISSNs: 1359-4311

Abstract

Highlights: Sodium silicate-based sealant was investigated for use in a recuperator. Small-scale clamped plate-style recuperator designs were built and tested. A cold-side effectiveness of 82.5% was found for the recuperator core in experiment. A total pressure loss of 24.9 kPa was found for the recuperator core in experiment. A validated mathematical model was applied to a solar Brayton cycle recuperator. Abstract: A large, efficient recuperator is required for high cycle efficiency in a solar Brayton cycle (STBC) with an open-cavity solar receiver and air as working fluid. A recuperator often requires complex and costly manufacturing methods. In this work, a clamped plate-type recuperator with a metal gasket is investigated, together with a low-cost high-temperature sodium silicate-based sealant. Experimental investigations were performed to validate a mathematical model using a novel bone-shape design as well as a wide-channel design. The high-temperature sealant worked well on the bone-shape recuperator; however, a leak occurred on the hot-side header tube of the wide-channel recuperator. For the recuperator core of the wide-channel test rig, a cold-side effectiveness of 82.5% and a total pressure loss of 24.9 kPa were found at an average mass flow rate of 0.74 g/s per channel. The validated mathematical model was used in a parametric study to analyse the performance of the recuperator in an STBC by taking the stress and deflection of the plates into consideration. Results show that, for a total mass flow rate of 0.06 kg/s, a cold-side effectiveness of 90% and total pressure loss of less than 5% could be achieved, if a spacer is implemented to prevent deflection.