Active Thermal Cooling Technologies - Low Energy Cooling for Sustainable Buildings - page 118

area. The driving heat temperature was 82 ◦ C and the cooling water temperature was
28 ◦ C for 7 ◦ C cold water temperature (Lamp and Ziegler, 1997). The production of
these ACMs was stopped and the technology's licence was given to the Japanese
company Yazaki. Up to the beginning of the 1990s, Yazaki offered H 2 O/LiBr ACMs
with 5-10 kW cooling power (such as the WFC-600 with 7 kW), which were used for
solar cooling projects. Due to falling demand, the production was eventually stopped.
At the beginning of the 1980s, Arkla developed a double effect H 2 O/LiBr ACM in
which the lower temperature generator was supplied with solar energy, while in fossil
mode the double effect generator was fired using the higher COP. Due to the lack of
demand for solar cooling, the production of this cooling machine was stopped and the
technology was also licensed to Yazaki. The company sold the machines for several
years, but they are no longer available today.
In the following, selected past and current international projects are described
which consist of partly solar-assisted or completely solar-powered water- or air-cooled
single effect water/lithiumbromide ACM. Ageneral viewof some oldH 2 O/LiBr ACM
projects before 1979 is extensively presented in Loewer (1978). As there is not much
experience available with solar cooling installations, the main focus of the study is to
summarize the dimensioning of the solar collector field and storage tank in relation
to the cooling machine capacity, operating experiences and temperature levels used
and the associated costs. A simulation-based method for solar cooling system design
is then presented in Chapter 6.
Projects with Single Effect ACMs
In the medium-sized performance range, most project experience of solar cooling
relates to the single effect water/lithium bromide ACM WFC-10 from Yazaki, with a
cooling power range of 35-46 kW. There are only a few published results concerning
COPs, but the operation is generally rated as dependable and unproblematic.
An early solar cooling project involved the cooling of a winery of the Groupement
Interproducteurs du Cru Banyuls in southern France, set up in 1991. The wine cellar is
operated by aYazakiWFC-15with 52 kWcooling capacity and 130m 2 of vacuum tube
collectors (VTCs) with only 1.0m 3 of hot water storage. The operating heating input
temperature T h is 80 ◦ C and the reached COPs 0.57-0.58 (Quinette and Albers, 2002).
The Hotel Belroy in Benidorm, Spain, is also an early project where a 125 kW,
single effect H 2 O/LiBr ACM has been used since 1992. There are 344.5m 2 of VTCs
and three hot water storage tanks each with 12m 3 installed for the required heat input.
The ACM reaches COPs between 0.5 and 0.6 at heating temperatures of 96/86 ◦ C,
cooling water temperatures T c of 29/36 ◦ C and cold temperature levels T o of 14/9 ◦ C
(Hansen, 1993a).
Another project is the air-conditioning of the office building of the J. Wolferts
GmbH company in Cologne-Porz, Germany (1995). Two solar-driven 46 kWWFC-10
ACMs are installed for an air-conditioned surface over four floors of 1628m 2 and are