Session: 06-01: Thermal Energy Storage

Paper Number: 132981

132981 - Modeling of Hot and Cold Storage Silos With a Moving Packed-Bed Shell-and-Plate Heat Exchanger in a Particle Based Concentrated Solar Power System 

Abstract: 

Previous work in particle based concentrated solar power systems (CSPs) has focused on individual component level modeling. This focuses on the integration of the storage silos with the heat exchanger that transfers the heat from the hot particles to the working fluid of the power block. The system is based on the design requirements laid out in the Gen 3 Particle Pilot Plant (G3P3) at Sandia National Laboratory. CARBO HSP 40/70 acts as the heat transfer material that is heated in a solar receiver. These carbon coated ceramic particles are then transported from the receiver to the hot storage silo. Particles are then released periodically into the heat exchanger where heat is transferred to the power block working fluid which is supercritical carbon dioxide in this design. The particles then flow to the cold particle storage silo where they eventually are reheated in the solar receiver. 

The heat exchanger is a moving shell and plate heat exchanger design based on work completed by Albrecht and Ho. The computational model solves for the outlet temperatures of the particle and gas streams, as well as the temperature of the wall separating the two flows. This study will expand upon the current model to track other transients in the heat exchanger. When coupled with the storage silos, the impact of varying particle mass flow rates on the heat exchanger can be tracked as well. 

In CSP systems there is a storage silo for the hot side and a silo for the cold side. The design in this paper sizes the storage silos with the intent to store particles for 10 hours. Over this 10-hour period the particles should only drop by less than 15°C. This paper presents a unique modeling approach where the silo is modeled quasi-one-dimensionally similar to a fin. Conduction through particles is the primary mode of heat transfer and this is coupled to the insulation layers using an overall heat transfer coefficient. Also unique to this model is the use of the ZBS model for heat conduction coefficient in a packed particle bed. The ZBS model incorporates interparticle radiation to generate an accurate picture of heat conduction. The goal of this section is to track temperatures of the particle bed and the insulation materials. 

Integrating both components together allows for large system scale simulations. This paper would study how changes at both ends of the system effect the sub components. For example, how does changing the heat requirements of the power block effect the flow rate out of the hot storage silo? Tracking transient changes helps to spot potential problems such as thermal expansion limitations within the walls of the storage silo or heat exchanger. A fully integrated transient model of the storage and heat exchanger represents crucial step forward in a system level CSP mode. 

 

Presenting Author: Matthew Marton Georgia Institute of Technology

Presenting Author Biography: Matthew Marton is a graduate student at the Georgia Institute of Technology. His research is directed towards renewable energy systems and in particular concentrated solar power, hydrogen, and electrolytic cells.

Authors:

Matthew Marton Georgia Institute of Technology
Juan Camilo Nanclares FAMU-FSU College of Engineering
Juan Ordonez Florida State University - Florida A&M University
Jesus Arias Georgia Institute of Technology
Comas Haynes Georgia Institute of Technology