skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Experimental characterization of pressure drops and channel instabilities in helical coil SG tubes

Abstract

Helical tube heat exchangers provide better heat transfer characteristics, an improved capability to accommodate stresses due to thermal expansions and a more compact design with respect to straight tube heat exchangers. For these advantages they are considered as an option for the Steam Generator (SG) of many new reactor projects of Generation III+ and Generation IV. In particular, their compactness fits well with the requirements of Small-medium Modular Reactors (SMRs) of integral design, where all the primary system components are located inside the reactor vessel. In this framework, thermal hydraulics of helical pipes has been studied in recent years by Politecnico di Milano in different experimental campaigns. Experiments have been carried out in a full-scale open loop test facility installed at SIET labs in Piacenza (Italy)), to simulate the SG of a typical SMR. The facility includes two helical pipes (1 m coil diameter, 32 m length, 8 m height), connected via lower and upper headers. Following recently completed experimental campaigns dedicated to pressure drops and density wave instabilities, this paper deals with a new experimental campaign focused on both pressure drops (single-phase flow and two-phase flow, laminar and turbulent regimes) and flow instabilities. The availability of a large numbermore » of experimental data, in particular on two-phase flow, is of fundamental interest for correlation development, model validation and code assessment. Two-phase pressure drops have been measured in adiabatic conditions, ranging from 200 to 600 kg/m{sup 2}s for the mass flux, from 30 to 60 bar for the pressure and from 0.1 to 1.0 for the flow quality. The channel characteristics mass flow rate - pressure drop has been determined experimentally in the range 10-40 bar, varying the mass flow rate at a fixed value of the thermal flux. In addition, single-phase pressure drops have been measured in both laminar and turbulent conditions. Density wave instabilities have been studied at mass flux from 100 to 400 kg/m{sup 2}s and pressure from 10 to 20 bar, to confirm the particular behavior of the stability boundary in helical geometry at low pressure and low mass flow rate. Finally, starting from the unstable regions identified from the experimental channel characteristics, Ledinegg type instabilities have been investigated to drawn stability maps with complete stable and unstable regions in the dimensionless plane N sub-N pch. (authors)« less

Authors:
; ; ;  [1]
  1. Politecnico di Milano, Dept. of Energy, Nuclear Engineering Div. - CeSNEF, Via La Masa 34, 20156, Milano (Italy)
Publication Date:
Research Org.:
American Nuclear Society, 555 North Kensington Avenue, La Grange Park, IL 60526 (United States)
OSTI Identifier:
22107852
Resource Type:
Conference
Resource Relation:
Conference: ICAPP '12: 2012 International Congress on Advances in Nuclear Power Plants, Chicago, IL (United States), 24-28 Jun 2012; Other Information: Country of input: France; 20 refs.; Related Information: In: Proceedings of the 2012 International Congress on Advances in Nuclear Power Plants - ICAPP '12| 2799 p.
Country of Publication:
United States
Language:
English
Subject:
42 ENGINEERING; 22 GENERAL STUDIES OF NUCLEAR REACTORS; DENSITY; DESIGN; EXPERIMENTAL CHANNELS; FLOW RATE; HEAT EXCHANGERS; HEAT TRANSFER; INSTABILITY; NUCLEAR POWER PLANTS; PIPES; PRESSURE DROP; REACTOR VESSELS; STABILITY; STEAM GENERATORS; THERMAL EXPANSION; THERMAL HYDRAULICS; TURBULENCE; TWO-PHASE FLOW

Citation Formats

Colombo, M., Cammi, A., De Amicis, J., and Ricotti, M. E. Experimental characterization of pressure drops and channel instabilities in helical coil SG tubes. United States: N. p., 2012. Web.
Colombo, M., Cammi, A., De Amicis, J., & Ricotti, M. E. Experimental characterization of pressure drops and channel instabilities in helical coil SG tubes. United States.
Colombo, M., Cammi, A., De Amicis, J., and Ricotti, M. E. Sun . "Experimental characterization of pressure drops and channel instabilities in helical coil SG tubes". United States.
@article{osti_22107852,
title = {Experimental characterization of pressure drops and channel instabilities in helical coil SG tubes},
author = {Colombo, M. and Cammi, A. and De Amicis, J. and Ricotti, M. E.},
abstractNote = {Helical tube heat exchangers provide better heat transfer characteristics, an improved capability to accommodate stresses due to thermal expansions and a more compact design with respect to straight tube heat exchangers. For these advantages they are considered as an option for the Steam Generator (SG) of many new reactor projects of Generation III+ and Generation IV. In particular, their compactness fits well with the requirements of Small-medium Modular Reactors (SMRs) of integral design, where all the primary system components are located inside the reactor vessel. In this framework, thermal hydraulics of helical pipes has been studied in recent years by Politecnico di Milano in different experimental campaigns. Experiments have been carried out in a full-scale open loop test facility installed at SIET labs in Piacenza (Italy)), to simulate the SG of a typical SMR. The facility includes two helical pipes (1 m coil diameter, 32 m length, 8 m height), connected via lower and upper headers. Following recently completed experimental campaigns dedicated to pressure drops and density wave instabilities, this paper deals with a new experimental campaign focused on both pressure drops (single-phase flow and two-phase flow, laminar and turbulent regimes) and flow instabilities. The availability of a large number of experimental data, in particular on two-phase flow, is of fundamental interest for correlation development, model validation and code assessment. Two-phase pressure drops have been measured in adiabatic conditions, ranging from 200 to 600 kg/m{sup 2}s for the mass flux, from 30 to 60 bar for the pressure and from 0.1 to 1.0 for the flow quality. The channel characteristics mass flow rate - pressure drop has been determined experimentally in the range 10-40 bar, varying the mass flow rate at a fixed value of the thermal flux. In addition, single-phase pressure drops have been measured in both laminar and turbulent conditions. Density wave instabilities have been studied at mass flux from 100 to 400 kg/m{sup 2}s and pressure from 10 to 20 bar, to confirm the particular behavior of the stability boundary in helical geometry at low pressure and low mass flow rate. Finally, starting from the unstable regions identified from the experimental channel characteristics, Ledinegg type instabilities have been investigated to drawn stability maps with complete stable and unstable regions in the dimensionless plane N sub-N pch. (authors)},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {2012},
month = {7}
}

Conference:
Other availability
Please see Document Availability for additional information on obtaining the full-text document. Library patrons may search WorldCat to identify libraries that hold this conference proceeding.

Save / Share: