W. Mittelbach, T. Btittner and R. Herrmann

SorTech AG, Weinbergweg 23, 06120 Halle, Germany, walter. mittelbach@sortech. de

ABSTRACT

Beside the well-known liquid absorption chillers with LiBr-water as sorption pair also solid adsorption chillers may be used for generating chilled water with low-temperature heat. In the range of cooling capacities of 70 kW and higher Japanese products are on the market for many years using silica gel as adsorbent and water as refrigerant. But due to the much larger volume and weight of the machines compared to LiBr absorption chillers adsorption chillers only found niche markets up to now. The main reason for the large volume of the adsorption chillers sold up to now is the low heat transfer rate between silica gel and the heat exchanger surfaces. SorTech AG developed a coating process, which enables to apply heat exchanger surfaces directly with the adsorbent. This enabled the development of more compact and lightweight adsorption chillers. Based on this technology SorTech AG developed a small adsorption chiller with a nominal cooling capacity of 7.5 kW. The objective is to provide a compact machine, which may be used for solar air-conditioning in private homes and small offices.

Keywords: adsorption chiller, solar cooling, silica gel