Passive Thermal Management for a Fuel Cell Reforming Process

Abstract

The US Navy is investigating hydrogen fuel cells powered by reformed naval logistic diesel fuel as a means of providing distributed ship service electrical power. Operation on diesel fuel requires a reformer system to remove sulfur and convert the synthesis gas into a hydrogen rich stream. Temperature control of the reformer system is made difficult because rapid changes in the fuel cell electrical load require rapid changes in the reactant flow rate. The current valve-based control system has several drawbacks, including increased system volume and pressure drop and decreased reliability. A heat exchanger based on Variable Conductance Heat Pipes (VCHP-HX) is currently under development. The VCHP-HX can passively regulate reactant temperature without a control valve and its attendant disadvantages. This paper presents the results to date of a VCHP-HX development program, including compatibility testing of candidate working fluid and wall materials, test data from a single VCHP, and test results from an array of VCHPs operating at reduced temperature. Suitable working fluids have been identified and the test results show good agreement with model predictions.

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Document Details

Document Type
Technical Report
Publication Date
Jun 01, 2006
Accession Number
ADA505568

Entities

People

  • David B. Sarraf
  • Denis Colahan
  • Richard W. Bonner

Tags

Communities of Interest

  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Cells
  • Control Systems
  • Diesel Fuels
  • Efficiency
  • Energy
  • Equations
  • Failure Mode And Effect Analysis
  • Flow Rate
  • Fuel Cells
  • Gases
  • Heat Energy
  • Heat Pipes
  • Heat Transfer
  • Heat Transfer Coefficients
  • Temperature Control
  • Temperature Gradients
  • Thermal Resistance

Readers

  • Combustion and Flow Dynamics.
  • Petroleum Engineering
  • Systems Analysis and Design

Technology Areas

  • Biotechnology