Effects of Reinsulating Underground Steam Pipes- A Case Study

Abstract

District heating and steam distribution through an underground network of pipes dates back to the late 1800s. Many systems exist today with piping networks that exceed 50 years of service life. The age of these systems has taken its toll resulting in the thermal inefficiency of the network. The Department of Energy (DOE) estimates there are 20,000 miles of heat distribution pipes. Millions of dollars a year are lost due to the ineffective thermal efficiency of these pipes. This inefficiency contributes to excess fuel burned at the plant, resulting in excess emissions that contribute to global warming. Steam distribution networks exist in major metropolitan areas, military bases and university campuses. The costs to replace these systems due to poor thermal efficiency would cost billions of dollars. In most cases, the steel carrier pipe is still in good condition and the outer conduit is intact; however, the insulation surrounding this pipe has degraded or fallen off and washed away. The objective of our group was to develop a way to re-insulate buried underground networks and provide a cost-effective alternative to replacement. The case study being presented indicates that ConduFill is a viable solution for many applications.