Advanced Liquid Desiccant-Based Air Conditioning Systems

About M. Conde Engineering

Started 1992, M. CONDE ENGINEERING concentrated initially on the development of simulation tools for HVAC&R equipment.

1997 marked a departure from this field, as our interests and activities shifted to development and design of Air Conditioning (AC) equipment, preponderantly to Devepment & Design of thermally driven AC devices. Since then, we have become ever more convinced that, with few exceptions, AC equipment ought to be thermally driven1!

Since 2002 we have concentrated our activities on the development of Open Absorption-Based AC Systems LDACS — i.e. absorption systems operating at atmospheric pressure, using as operating fluids the air to be conditioned, water and a Liquid Desiccant.

We have systematically pursued the development of LDACS technology from its state in 2002, namely by:

Analysing the state-of-the-art and identifying where immediate development work would be required;
Undertaking to establish methods for the calculation of liquid desiccant properties, as required in the simulation and design of LDACS2;
Studying which technological solutions might exist to overcome the barriers that were (and are) on the way of a faster spread of LDACS;
Developing and testing various techniques to master the single most serious problem posed by LDACS in their state-of-the-art — CORROSION3;
Establishing and designing manufacturing methods for the components of (A)LDACS that incorporate the new developed techniques.

Comments & References

[1] There are strong reasons to move away from mechanically driven AC devices, in particular of the vapour compression kind. These reasons have thermodynamical, economical, and ecological, not to say ethical.

They can be summarized in one short sentence: — Degrade resources (in particular energy resources) with just the lowest potential level required for their final use!

An example: Fossile fuels, such as natural gas, can be used to drive systems requiring temperatures in the high hundred Celsius. Why then use them to warm-up water just to 60 °C or even less ?

In fact rejected effluents of the higher temperature application are absolutely suitable for hot water preparation!

[2] Conde, M. R. 2004. Properties of aqueous solutions of lithium and calcium chlorides: Formulations for use in air conditioning equipment design, Int. J. of Thermal Sciences, 43, 367-382.

[3] Conde-Petit, M. et al. 2008. Open Absorption System for Cooling and Air Conditioning Using Membrane Contactors — Final Report