(350a) Treated Waste Water Source Heat Pump Design and Improvement

A water source heat pump is a central heating/cooling system that pumps energy to or from water to provide heating or air conditioning. It is an efficient alternative to conventional heat, ventilation and air conditioning (HVAC) systems. Waste water treatment facilities provide easy access to large bodies of water which can be readily harvested. Such system generally lead to an almost 50% reduction in energy cost, and can therefore play an important role in maintaining and improving a sustainable ecosystem. The high flow rate and almost constant water temperature in such facilities make them especially attractive energy sources for heat pumps. We have collaborated with Metropolitan Water Reclamation Department of Greater Chicago (MWRDGC) to design and test different layouts of water source heat pump including open and close loops systems. The test data obtained will be used to increase the efficiency and lower maintenance costs, which will significantly reduce the cost of energy usage at the site. The test system has been installed at the Kirie Waste Water Treatment Facility in Des Plaines, IL. The system will in the future be further improved by using Phase Change Materials (PCMs) to take  advantage of large latent heat of (about 250kJ/kg) PCMs to store energy during off-peak hours and release it during peak hours. This will reduce overdesign of the system and lower the initial capital cost. The entire process has also been simulated using the Aspen Plus simulation package and these simulations will allow us to further increasing the efficiency in the future as well. This project is a modest contribution to the development of more sustainable energy systems.