Heat exchangers are being used in everything from refrigerators, air conditioning units to car heaters. However, they have had limitations in what their efficiency is concerned.
Not anymore – reinventing the wheel, Georgios Vatistas improved the heat exchanger and made it some 40 times more efficient than the traditional model. This could mean huge energy savings for everybody. Vatistas is a professor in the Department of Mechanical and Industrial Engineering at Concordia University, in Montreal, Canada. He now hopes his design will revolutionize how efficiency is seen in each and every industry.
“Ultimately,” he says, “this heat exchanger will have broad use across countless sectors. By responding to industrial needs with a more sustainable solution, we’re showing that the future of engineering can be a green one.”
Vatistas’s predominant background is in vortex flows. After studying more than 20 years how water and air flows, the professor realized that swirling could dramatically increase heat transfer exchange.
In 2010 he also got the “Idea to Innovation” (I2I) $115,452 grant from the Natural Sciences and Engineering Research Council to finish his work.
Update: Mr. Vatistas sent us an e-mail regarding his invention, thus clarifying the efficiency figure mentioned in the Eurekalert! article earlier:
My response to the comments made by the reader
With respect to the statement: “Are there any engineers reading this. It seems to me that the claim of 40 times more efficient ? is pretty absurd. Surely current heat exchangers would have to be less than 3% efficient ? in order for a new kind of exchanger to be able to be 40 times more efficient. Otherwise they would become more than 100% efficient (impossible).” I have the following to say.
It is true that when the word efficiency is mentioned, in connection to a system that involves heat, we immediately think of the thermal efficiency of a heat engine (power producing cycle) defined as benefit divided by cost. The last of course cannot exceed the value of 1 (or 100%, in fact less, let us not forget also Carnot’s efficiency)*. However, the present device is not a heat engine but rather a component operating within a system. For a fair comparison, we gave the proportional usefulness between two different designs (new and traditional), as a ratio of the energy demands (cost), for the same amount of heat transferred (benefit), and inlet conditions.
In the media release, the mentioned efficiency involved the power supplied by the pumps to circulate the two fluids through the device. The assessment of the new design was made using data from actual heat exchangers provided by two manufacturers. The figure given in the release pertains to the plate class, known to consume relatively large amounts of energy, as a trade off for compactness. The results of our investigations have indicated that for the same energy transfer and inlet conditions, the new device consumes 40 times less energy than the traditional. The lower energy consumption trait of the new design is also present in our comparisons with the Shell & tube type (in this case is 4-6 times less). Furthermore, for a matching heat transfer, the size of the new equipment is substantially less than the Shell & tube.
In retrospect, perhaps instead of: “… is 40 times more efficient than the traditional model.”
we could have used: “… it requires 40 times less energy to operate than the traditional model.”
In response to: “Wouldn’t it be nice if journalists would insist on some hard data? so that we could evaluate their outrageous claims?” I would like to mention that the present document is a media release based on our investigations and the fully documented technical report of our investigations will be submitted to Natural Sciences and Engineering Research Council by early April.
Georgios Vatistas, Principal investigator and co-inventor
* Note that: for a refrigeration cycle its effectiveness is given by the coefficient of performance (COP) for cooling, which could be more than 1.