SOLID-STATE COOLING WITH PRESSURE: DEVELOPEMENT OF BAROCALORIC COOLING DEVICE (COOL PRESS)

Refrigeration and air-conditioning are crucial for modern society, but our standard vapor-compression refrigeration technology is old, relatively inefficient and still environmentally harmful. In recent years caloric cooling technologies have shown the greatest potential as a serious alternative to vapor-compression technology. They are utilizing solid-solid phase transformation and can be more efficient and completely harmless to the environment. Among them, barocaloric cooling stood out recently due to colossal transformational latent heat and entropy changes in some materials when subjected to hydrostatic pressure. The entropy changes in some of the best barocaloric materials (e.g., plastic crystals) are now comparable to entropy changes of vapor-compression refrigerants and are for an order of magnitude larger compared to other known caloric materials. This opens up new avenues in designing efficient and powerful caloric devices. However, no demonstrative proof-of-concept barocaloric device has been design, built and tested to date, which is the main goal of the COOL PRESS project. In order to reach this goal, we will answer two fundamental questions of barocaloric technology, which have not yet been sufficiently addressed. First, how to generate the required (relatively high) hydrostatic pressure in an efficient way and how to utilize the work released during depressurizing at the same time. Second, how to transfer heat between barocaloric material and heat sink/source in the most efficient way. The project is structured around five ambitious, beyond the state-of-the-art objectives. We are proposing a bottom-up comprehensive experimental and theoretical (numerical) investigation of different heat transfer solutions and different pressure generation systems that will be combined into the world-first barocaloric device. This will be achieved within five interconnected work packages. Supported with our extensive experiences in designing (other) caloric cooling devices, we are targeting a breakthrough in cooling technologies that would pave the paths for further development of barocaloric technology, and in long-term provide greater efficiency and reduced levels of pollution, by applying environmentally harmless solid-state refrigerants.