IEA Solar Heating and Cooling Programm - NachhaltigWirtschaften.at

IEA SHC Task 38 Solar Air Conditioning and Refrigeration Subtask A Report A-D3b, Date: December 2010
Use of auxiliary heating system
Auxiliary chiller
Space heating in winter, DHW and cooling
no
System scheme
System performance
An average thermal COP for the period between the 21st of August and the end of
September of 0.565 could be reached. Electrical COPs range in daily values from 0.5 to 5
and achieve an average value of 3.1. In the period between the 11th and 18th of September
no results were monitored due to a data processing problem of the computer system.
System reliability and overall success of the installation
In the time where the plant was running, it worked quite well. Nevertheless the average
values over a longer time period are still improvable. In the beginning of the cooling season
problems did occur due to the low volume flow of the solar cycle, therefore the mode was
changed to maximum speed. Now the solar pumps are working in summer times without
rpm-regulation.
During the monitoring period some problems did occur including monitoring and control
system problems. The wet cooling tower works very well in the Gröbming climate. At a
glance the PSC12 Pink chiller fulfilled the promised thermal COPs at the different driving,
cooling and recooling temperatures. Considering the other parts of the system, such as the
heating of the swimming pool, the hot storages or the district heat the complete hydraulic
scheme gets overloaded and not clearly arranged at the first look.
Summarizing five main practical suggestions for improvement have been found:
- adapting the control system in order to make clear division between heating and
cooling periods
- including the cooling cycle of the DHW priority rule
- excluding the logical test room temperature >24°C of the control strategy in order to
use the concrete core activation as a storage and make the control system easier
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