Cooling System Driven by Industrial Low-Grade Waste Heat

The present use of renewable energies leaves one of its sectors either underutilized or even neglected. This is an ultra-low temperature heat (below 170F), which constitutes over 70% of waste heat in the industry and is relatively easy to recover. The cost-effective systems that convert such heat for useful cooling, air-conditioning (A/C) or even electricity generation could be a breakthrough innovation. Indeed, conventional refrigeration and A/C sector consumes over 25% of all electricity generated in the USA and creates significant environmental hazards. Responding to these needs, Marani USA, Inc. proposes to develop a new technological platform for ejector-based cooling, which will be environmentally clean and cutting the electricity use by more than 80%. The innovation is a new thermodynamic cycle where compressor is replaced by a supersonic vapor-to-vapor ejector, which pressurizes the refrigerant from evaporator to condenser level by a shockwave. This is the first-time proposition to develop, design and build the prototype of a cooling system that would be ejector-based, scalable and powered by ultra-low-temperature industrial waste heat. Although a possibly similar thermodynamic cycles have been studied in the past, nothing practical was ever demonstrated neither in laboratory or commercially. Therefore, this project presents major challenges both scientific and technological, where new solutions have to be created or even invented. The objective of Phase I will be to design and demonstrate the key enabling technologies needed to produce a fully functioning prototype of ejector cooling system in Phase II. The most significant technological innovation needed is the design of an ejector itself, capable to work within a specific refrigeration cycle. Shockwaves will be studied for environmentally friendly refrigerants and numerical modeling with experimental validation will be conducted for supersonic ejector. As the final result, the geometrical design of ejector is expected to emerge plus its application within a refrigeration system. The first application, suggested by potential customers, will be a system for industrial cooling and A/C powered by industrial waste heat generated during air compression. The research will be directed towards producing cool at standard parameters for A/C. i.e. water at 43F return at 54F and adjusted for high temperature cooling - air at 61F. Separately, a cool for industrial processes can be produced at 32-46F. Overall, the market for the proposed technology is large because waste heat generated during air compression alone costs the national economy $4-5 billion by conservative estimates. The above approach leverages 20+ years of our team experience with refrigeration, fluid flow and thermodynamics. If the project is successfully carried over to Phase II, the line of attractive, heat-powered refrigeration and A/C equipment, minimizing the need for electricity and maintenance will be developed. Many applications are envisioned beyond the one described, examples being post-harvest storage of food and vegetables, cooling in field hospitals, command centers and data/computer rooms. A significant potential exists in Third World and in remote areas where electric energy is limited or unavailable.