and Cooling technology Page 76
As with the
absorption heat pump, the heat quantity diverted in the condenser is more or
less identical to that of the heat supplied to the evaporator, and the heat
diverted in the absorber is more or less the same as that supplied to the generator.
The heat quantity Q1' absorbed from the evaporator is set equal to 1. The heat
Q2 = 2 / (1 - 2)
from the absorber can then be diverted to the user. The condenser heat Q0 is
also equal to 1; the heat Q2 = 2
/(1 - 2) must be directed
to the generator. The heat relationship 2
typically lies at 0.40 to 0.45.
The attempt to develop a demonstration model for solar cooling during the course
of the SERVITEC project has shown two things:
Fig. 60 Demonstration model
of a solar absorption refrigeration machine
- It is in principle entirely
possible to realise the theoretical considerations from a technical standpoint.
This takes as a prerequisite, of course, the application of high quality electronic
measuring devices. The calculation of energy balances also demands corresponding
software and a PC for the recording of measurement data, its evaluation and
- The solar energy at
our disposal during a presentation in Barcelona an October 3rd, 2000 was not
sufficient to attain the optimal expulsion temperatures of the generator with
the help of two vacuum collector tubes.
We were, however, able to solve this problem in two ways. First, the solar
collector surfaces could be correspondingly enlarged. However, this would
only be of help where sunshine was present. A more productive solution would
be the installation of a second energy source for re-heating, whereby the
solar energy would function as a pre-heating step in the work process.
The present model is already
very suitable for the demonstration of the functionality of a solar absorption
refrigeration machine, but must be expanded with industrial components, especially
a re-heating step, in order to sufficiently prepare prospective service technicians
for what awaits them one day in practice.
The contribution of the Fraunhofer Institute for Solar Energy Systems in Freiburg,
which is included in the appendix to this MODULE III, shows, however, that even
industrially produced solar air-conditioning plants only appear sporadically,
and therefore still have the character of pilot plants.