Energy Piles Design Parameters Optimization by using Fuzzy Logic

Abstract

Energy pile uses environmental-friendly technology, i.e. low carbon footprint and greenhouse gas (GHG) emissions, and cost-effective. The use of energy piles have been increasingly grown due to the combination of their transferring load from structure into the bearing layer and exchanging of heat with the soil, i.e. environmental benefits. Energy Piles are used renewable energy designed to utilize the relative constant temperature of the soil (soil energy: geothermal) that surrounds the energy piles for heating and cooling of buildings by the use of ground source heat pump (GSHP). Energy piles have been harvesting energy from the soil that surrounds the piles by using buried pipe networks which aims to reduce their carbon footprint and to increase the energy efficiency of the building, i.e. to have energy-efficient building. In the study the design parameters of energy piles (diameter/size/length of pile and type of foundation, length/diameter/thickness/location of pipe pattern inside energy piles, dimensions & the arrangement/pattern of energy piles and pipes, type of concrete, and fluid characteristics inside pipes, power & location of GSHP, diameter & length of energy piles, soil thermal properties & soil temperature, groundwater level,  depth to bedrock,  type of concrete, type of GSHP, type of fluid inside pipes, pipe configuration inside energy piles…, i.e. all related design parameters) that affect their design of energy pile and related pipes are evaluated by using fuzzy logic. The thermal efficiency of energy piles improves significantly by increasing the number & configuration of pipes inside the energy piles and by adding thermally conductive materials to the concrete within acceptable limits. By using Fuzzy method; the calculated criteria weights for energy piles design parameters’ weights are as follows: the most important evaluation dimension/main-criteria is “Soil thermal properties & Soil temperature”, the second important evaluation dimension is “Pipe configuration inside Energy Piles” and the third important evaluation dimension is “Diameter & length of energy piles”. By using energy piles buildings will have minimum carbon footprint and will be environmental-friendly green buildings.