- Author
- Fang, J. B.
- Title
- Minimum Life Cycle Cost Heat Losses for Shallow Trench Underground Heat Distribution Systems.
- Coporate
- National Bureau of Standards, Gaithersburg, MD
- Sponsor
- Army Corps of Engineers, Washington, DC Naval Facilities Engineering Command, Alexandria, VA Air Force Engineering and Services Center, Tnydall AFB, FL
- Report
- NBSIR 86-3381, May 1986,
- Distribution
- Available from National Technical Information Service
- Keywords
- pipes (tubes); heat loss; thermal insulation; heat transfer; life cycles; service life
- Identifiers
- heat pipes
- Abstract
- The rates of heat loss from two underground insulated pipes installed in a shallow trench were calculated using a computer program developed based on the application of the finite element method to solution of two-dimensional steady heat conduction problems. The calculated results of pipe heat loss under a specified ground temperature condition are summarized for a range of pipe insulation thickness, different sizes of shallow trench, and various pipe fluid temperatures. Methods of determining the minimum life-cycle cost heat loss and the corresponding economic insulation thickness for shallow trench heat distribution systems are presented. Life-cycle costing analysis was performed for two insulated pipes in a concrete trench to determine the cost of construction, annual energy cost associated with pipe heat loss, and yearly operating and maintenance costs.