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
Nano-scale process may speed arrival of cheaper hi-tech products
09.11.2018 | University of Edinburgh
Nuclear fusion: wrestling with burning questions on the control of 'burning plasmas'
25.10.2018 | Lehigh University
Biochips have been developed at TU Wien (Vienna), on which tissue can be produced and examined. This allows supplying the tissue with different substances in a very controlled way.
Cultivating human cells in the Petri dish is not a big challenge today. Producing artificial tissue, however, permeated by fine blood vessels, is a much more...
Faster and secure data communication: This is the goal of a new joint project involving physicists from the University of Würzburg. The German Federal Ministry of Education and Research funds the project with 14.8 million euro.
In our digital world data security and secure communication are becoming more and more important. Quantum communication is a promising approach to achieve...
On Saturday, 10 November 2018, the research icebreaker Polarstern will leave its homeport of Bremerhaven, bound for Cape Town, South Africa.
When choosing materials to make something, trade-offs need to be made between a host of properties, such as thickness, stiffness and weight. Depending on the application in question, finding just the right balance is the difference between success and failure
Now, a team of Penn Engineers has demonstrated a new material they call "nanocardboard," an ultrathin equivalent of corrugated paper cardboard. A square...
Physicists at ETH Zurich demonstrate how errors that occur during the manipulation of quantum system can be monitored and corrected on the fly
The field of quantum computation has seen tremendous progress in recent years. Bit by bit, quantum devices start to challenge conventional computers, at least...
09.11.2018 | Event News
06.11.2018 | Event News
23.10.2018 | Event News
15.11.2018 | Earth Sciences
15.11.2018 | Physics and Astronomy
15.11.2018 | Physics and Astronomy