“Absorption heat circulations represent a special type of cooling circulation used for transforming thermal energy between different temperature levels. The basic principle of absorption circulations is replacing the compression of coolant vapours using three thermo-chemical steps: absorption in a solution, pumping to a higher pressure level and desorption of vapours from the solution. This procedure enables the transformation of thermal energy to a higher temperature level with lower-order consumption of electricity compared with traditional compressor circulation.” Use of absorption circulation is widespread and is found, for example in absorption heat pumps, trigeneration, solar cooling and remote heat supply.(2)
(Source: Jiří Pospíšil)
The heat exchanger with partial absorption and desorption is made of a hollow jacket. The inner space of the exchanger is divided by a wall vertically situated in the desorption and absorption channel. The desorption channel is equipped with an inlet neck of coolant saturated solution in the jacket bottom area and an outlet neck of the cooled solution in the area of the jacket upper wall. The absorption channel is equipped with an inlet neck of coolant unsaturated solution in the jacket upper wall and an outlet neck of the heated solution in the area of the jacket bottom area. In both the desorption and absorption channel, sections of inbuilt couples are mounted, made of open hollow sections which are interconnected through transfer channels and are arranged in each of the channels above each other so that they create a labyrinth of opposite-facing passages for the flowing cooled or heated medium.
The structure of the newly-designed heat exchanger is compact and increases the thermodynamic efficiency of absorption circulations operated in the mode of cooling unit or heat pump. The invention enables the realization of heat transfer whilst minimizing the temperature gradient. The heat exchanger with partial absorption and desorption is protected by a patent and a utility model.
JIŘÍ POSPÍŠIL is an acknowledged expert in the field of applied thermo-mechanics and power engineering. Since 2001, he has been working at the Faculty of Mechanical Engineering of the Brno University of Technology, where he holds a position of associate professor (Doc.) at the Energy Institute, Department of Power Engineering, and at the same time he works in the Division of Power, Process and Environmental Engineering at NETME Centre. In his research activities he particularly deals with energy sources and methods how to utilize them most effectively, including the assessment of impacts on the environment. In 2007 he presented his inaugural dissertation entitled Numerical Modelling of the Transport of Suspended Particles Generated by Road Transport. He is an author of many scientific articles in both Czech and international scientific journals, and participates in a range of scientific projects.
(1) Heat exchanger. In: Wikipedia: the free encyclopedia [online]. San Francisco (CA): Wikimedia Foundation, 2001, 16. 9. 2012 [cit. 2012-10-25]. Available at: http://cs.wikipedia.org/wiki/Tepeln%C3%BD_v%C3%BDm%C4%9Bn%C3%ADk
(2) POSPÍŠIL, Jiří. Absorption circulations. In: Institute of Energy: Department of Power Engineering [online]. 2009, 30. 7. 2009 [cit. 2012-10-25]. Available at: http://oei.fme.vutbr.cz/absobehy.aspx
Photo: Sue Byford, Sxc.hu
