Did you know that more than 15% of the electrical energy produced in industrialized countries was consumed by cold production (12%) and air conditioning (3%)? Yet consuming kilowatts is increasingly expensive, reduces fossil fuel resources, and increases greenhouse gas emissions.
In the majority of refrigeration installations, the operating condition of the air condenser, located at the back of the unit, in contact with ambient air, is a decisive element in the amount of power consumed by the refrigeration unit.Cemagref research is being conducted to improve the energy efficiency of the condensers of cooling devices using humidification techniques. The objective is to develop an efficient and economical process that can be adapted to mid- and high-power refrigerating devices, as low as 10 kWh.
The humidification principle
We have all experienced a sensation of heat when passing behind a functioning refrigerator or air conditioner. The cause of this phenomenon is the air condenser, a heat exchanger made up of tubes with air fins attached to the back of the device. This is where the cooling fluid condenses by releasing its heat into the ambient air. To limit the system’s energy consumption, humidification processes were born. The principle consists of saturating the ambient air in contact with the exchanger by projecting fine water droplets. Humidification of the air intensifies the heat exchange on the air side and reduces the cooling fluid’s condensation temperature. This lowers the compression rate in the cooling cycle and improves the compressor’s consumption of electrical power.
- Making gains at every level
The process empirically applied needed to be optimized in view of its application to air conditioning and industrial refrigeration. Research was initiated in this context in 2006 by the ENERFRI team at Antony. A preliminary mathematical model made it possible to estimate the energy savings that could be made with an optimized humidification process, reaching up to 20% of the total electrical energy consumed. In addition, by integrating the humidification system at the design stage, it was possible to reduce the loads of cooling fluid by 10%. Knowing that most of these fluids are suspected of contributing directly to the greenhouse gas effect, the direct gain for the environment is substantial.
- Improving scientific knowledge
A pilot project is being constructed to understand the interaction between the humidity and a surface made up of tubes and air fins spaced 2–3 mm apart. The theoretical models will then be validated by varying the size and number of droplets measured by an optical granulometer. What is the optimal water flow to prevent the condensers from producing drops that flow on the air fins and obtain a maximum effect for a minimal water consumption? What is the optimal droplet size? How far from the unit should the humidifier be installed? These are the questions that Cemagref researchers are attempting to answer so as to define the optimal conditions for efficient and economical humidification of air condensers.
Marie Signoret | alfa
Harvesting the Sun for Power and Produce
24.11.2017 | Fraunhofer-Institut für Solare Energiesysteme ISE
Batteries with better performance and improved safety
23.11.2017 | Empa - Eidgenössische Materialprüfungs- und Forschungsanstalt
High-precision measurement of the g-factor eleven times more precise than before / Results indicate a strong similarity between protons and antiprotons
The magnetic moment of an individual proton is inconceivably small, but can still be quantified. The basis for undertaking this measurement was laid over ten...
Heat from the friction of rocks caused by tidal forces could be the “engine” for the hydrothermal activity on Saturn's moon Enceladus. This presupposes that...
The WHO reports an estimated 429,000 malaria deaths each year. The disease mostly affects tropical and subtropical regions and in particular the African continent. The Fraunhofer Institute for Silicate Research ISC teamed up with the Fraunhofer Institute for Molecular Biology and Applied Ecology IME and the Institute of Tropical Medicine at the University of Tübingen for a new test method to detect malaria parasites in blood. The idea of the research project “NanoFRET” is to develop a highly sensitive and reliable rapid diagnostic test so that patient treatment can begin as early as possible.
Malaria is caused by parasites transmitted by mosquito bite. The most dangerous form of malaria is malaria tropica. Left untreated, it is fatal in most cases....
The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.
Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...
Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.
That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...
15.11.2017 | Event News
15.11.2017 | Event News
30.10.2017 | Event News
24.11.2017 | Physics and Astronomy
24.11.2017 | Health and Medicine
24.11.2017 | Earth Sciences