Cryogenically Cooled Heat Pipes Used for Refrigeration

Scientists at Brunel University London, in collaboration with Air Products PLC, have engineered a new method to build freezers using advanced cryogenically cooled heat pipe technology. The units, capable of reaching temperatures as low as -180 °C, are likely to be used for medical storage, cooling and storing samples ranging from blood plasma to eggs, sperm and other biological materials.

“At the heart of the new system is the concept that what we needed was to be able to efficiently transfer cold,” says Dr. Hussam Jouhara, of Brunel’s Institute of Energy Futures. ““The cold in our design comes from liquid nitrogen. But unlike conventional cold storage using the liquefied gas, we don’t need to physically transfer the nitrogen. The cryogenic heat pipe is literally just moving the cold. In safety terms this has major implications as in the US alone eight deaths a year are attributed to nitrogen asphyxiation. Our innovations mean the gas tanks can be situated safely outside in the open air.”

The heat pipes have no moving parts and require no routine maintenance, according to engineers. The system also includes an energy recovery process the scientists say could result in as much as a 50 percent reduction in liquid nitrogen use compared to conventional equipment. “Liquid nitrogen is expensive in both cash terms and energy consumption to produce,” says Jouhara. “And quite rightly there are strict health and safety rules because of the attendant dangers of asphyxiation. The Brunel system has no such special requirements.”