Session: K6-08: HEAT TRANSFER IN ENERGY SYSTEMS - WASTE HEAT I

Paper Number: 131191

131191 - Pressure Controlled Heat Pipe Based Heat Exchanger for Dynamic Process Heat Extraction Control for Nuclear Power Plants 

Abstract: 

Nuclear power plants (NPP) are clean energy sources typically designed for baseload power operations and are typically incapable for dynamic responses. One method to improve the NPP flexibility is enabling technologies to extract process heat to support consumer operations or district heating needs. Typical shell and tube heat exchangers employed for heat extraction may be less suitable due to potential for tritium migration into the process stream. This study discusses a novel heat exchanger (HX) based on Pressure Controlled Heat Pipes (PCHPs) that ensures faster responses to varying heat load and mitigates challenges typical to conventional heat exchangers. To demonstrate this technology, a prototype PCHP-HX was fabricated with stainless steel 304. Here, only process heat extraction using this technology is discussed. The main stream, simulating heat extraction from the NPP and the process heat stream for operations were separated into two separate shells. DI water-based thermosiphons were installed in the two shells to transfer heat from the main stream (evaporator) to the process stream (condenser). To dynamically respond to heat loads, Non-Condensable Gas (NCG) was introduced into the thermosiphons to control heat transfer between the two streams. If NCG sweeps into the condenser, thermosiphon cannot reject heat and the heat transfer is stopped. From experiments, up to 6 KW heat transfer was demonstrated with main stream at 90 °C and with process stream flow rate of 3.78 liters/min. Lower flow rates reduced the heat transfer rate to some extent. Complete system shut-down was achieved within 7 minutes. To demonstrate start-up, the NCG was evacuated from the thermosiphons. Complete system start-up was achieved within 4 minutes with 100% heat delivery to the process stream. This work was funded by DOE Phase I SBIR award DE-SC0020778.

Presenting Author: Sai Kiran Hota Advanced Cooling Technologies, Inc.

Presenting Author Biography: Dr. Hota is an R&D engineer at Advanced Cooling Technologies, Inc. His work involves reserach, development and demonstration of novel thermal management technologies for various applications, primarily funded by SBIR/ STTR agencies.

Authors:

Sai Kiran Hota Advanced Cooling Technologies, Inc.
Andrew Lutz Advanced Cooling Technologies, Inc
Srujan Rokkam Advanced Cooling Technologies, Inc
Calin Tarau Advanced Cooling Technologies, Inc.