Q1-2 The HTRI Multipurpose Boiling Unit

L. W. Swanson

HTRI commissioned its newest experimental rig, the Multipurpose Boiling Unit (MBU), in October 1995. The unit consists of a flow loop and a flange-mounted test section that provides horizontal intube flow boiling data for pure fluids and mixtures. In the future, the MBU can be adapted to other test-section geometries such as an ideal tube bank or a single plate-and-frame heat exchanger channel.

The intube flow boiling data collected by the MBU will provide the following information on flow boiling phenomena inside horizontal plain and internally enhanced tubes:

  • Nucleate boiling suppression for pure fluids and mixtures
  • Convective and pool boiling heat transfer degradation due to mass transfer and vapor-liquid equilibrium (VLE) effects in mixtures
  • Critical heat flux for pure fluids and mixtures under flow boiling conditions
  • Flow regime definition (e.g., wet- or dry-wall conditions)
  • The influence of turbulators, twisted tapes, and other internal enhancements on multicomponent flow boiling processes

HTRI will use these data to improve and develop flow boiling correlations and mathematical models in our software and to establish a basis for future flow boiling experimentation.