Testing a More Sustainable Air Conditioning System
Funded through Round 1: Open Call in 2010, May-Ruben Technologies (MRT) conducted a research project to develop and demonstrate a novel, thermally driven binary fluid ejector (BFE). The primary goal of the project was to physically demonstrate the technical merit and measure the performance of a BFE system, including demonstrating the technology in a system designed for space cooling, specifically for building air conditioning.
The BFE technology’s objective is to provide a more efficient and environmentally friendly refrigeration system by utilizing waste heat instead of relying on conventional electric motor-driven compressors. The technology replaces the conventional electric motor-driven compressor with a gas-phase fluidic compressor called an “ejector”. This system is thermally driven, using a boiler to provide the necessary drive energy.
By harnessing waste heat, the system reduces the need for additional energy input, which is typically provided by burning fossil fuels in conventional systems. Unlike conventional refrigeration systems that rely on electric motor-driven compressors, the BFE system operates without significant electricity consumption. This reduces the demand on power plants, which are major sources of greenhouse gas emissions. By reducing the load on the electrical grid, particularly during peak cooling periods, the BFE system helps lower the reliance on fossil fuel-based power generation.
Understanding the Binary Fluid Ejector in a Variety of Operating Conditions
The BFE concept was successfully demonstrated under real-world space cooling operating regimes, achieving an acceptable and improved thermal coefficient of performance (COP) of 1-1.36. The most important lesson was that the use of a binary versus a single fluid for ejector refrigeration can offer a significant improvement in performance. However, under certain operating conditions, such as a high temperature gradient between the evaporator and the condenser, the ejector performance can be strongly affected. Consequently, a detailed literature review regarding these operating conditions based on real world application should be conducted as a follow-on.
What’s next?
Heat pumps similar to the BFE are gaining traction in the market, and space cooling is one promising application to improve efficiency and decarbonize buildings. The BFE technology is not yet widely used, but it is progressing towards commercialization. MRT is working toward bringing this technology to market by developing a commercial prototype and collaborating with partners to optimize and integrate the system into commercial applications.