Assessment of Direct Use of Geothermal Hot Water for Snow-Melting Pavements in Western North Dakota Using Finite Element Method

Abstract

Many advanced snow-melting methods for heating pavements have been studied, and the deep direct use (DDU) of geothermal hot water is considered to be a clean and economical resource for developing snow-melting pavement systems for cold regions. In western North Dakota, the cold climate hinders many economic activities due to the uncertainties associated with transportation. The presence of snow on roads and airport runways is a major problem, and thus, improving snow removal methods and transportation infrastructure in winter is vital to the economy and road safety. The use of geothermal hot water for snow-melting purposes provides a solution to these problems and has many advantages. In western North Dakota, the temperatures of geothermal hot water range between 30 °C to 130 °C, and water at these temperatures is available between 700 m and 3,500 m deep in several aquifers. These geothermal aquifers have been identified and are found to be able to supply good quality and abundant hot water. This paper focuses on two populated locations above these easily accessible aquifers. The paper considers the feasibility of a snow-melting system that uses DDU geothermal hot water based on heat transfer and the available heat supply. The heat requirements for melting snow are computed based on the climatic conditions in the studied areas using the Chapman and Katunich equations. Finite element analysis using COMSOL is employed to model the pavement heating processes, from pipes embedded in a concrete panel to the pavement surface according to the computed heat requirements. The heat supply also takes into account the cascading use of geothermal hot water for different temperatures, pipe properties, mass flow rates, reasonable water pressures, snow-melting efficiency, and the properties of concrete pavement panels. The feasibility of the proposed snow-melting pavement panels is assessed and an optimized design is recommended.