Effect of underground water attack on the performance of mineral wool pipe insulation

Book · Thu Dec 31 04:00:00 EST 1998

OSTI ID:687587

Chyu, M C ^[1]; Zeng, X ^[2]; Ye, L ^[3]

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1. Texas Tech Univ., Lubbock, TX (United States). Dept. of Mechanical Engineering
2. General Motors Corp., Troy, MI (United States). Advanced Technology Vehicles
3. Eaton Corp., Rochester Hills, MI (United States). Climate Control Engineering

The performance of mineral wool pipe insulation employed to insulate the underground pipes in district heating and cooling systems has been investigated when it is subjected to underground water attack. The pipe fluid temperature was tested from 35 F (1.6 C) to 450 F (232.2 C). The surrounding water was maintained from 46 F (7.7 C) to 100 F (37.7 C) to simulate the possible conduit water temperatures when the system fails. Under heated conditions (pipe temperature higher than water temperature), the effective thermal conductivity of the wet mineral wool insulation can be, depending on the insulation and the surrounding water temperatures, 50 times higher than that of dry insulation. The effective thermal conductivity data of wet insulation were correlated as functions of insulation mean temperature and surrounding water temperature. Correlations have also been developed in the form of a Nusselt number vs. a Rayleigh number. Under cooled test conditions (pipe temperature lower than water temperature), the effective thermal conductivity of saturated mineral wool is about 14 times higher than that of dry mineral wool. For both heated and cooled conditions, after drying, the effective thermal conductivity returned to the value before submersion.

• OSTI ID: 687587
• Report Number(s): CONF-980650--
• Country of Publication: United States
• Language: English

Related Subjects

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION
DISTRICT COOLING
DISTRICT HEATING
EXPERIMENTAL DATA
HEAT DISTRIBUTION SYSTEMS
MINERAL WOOL
MOISTURE
PERFORMANCE
PIPES
THERMAL CONDUCTIVITY
THERMAL INSULATION