The developing process has comprised design and production of process equipment and processing forms for paddle vanes and turbine casing as well as internal heat exchangers.

Although there are substantial technological challenges to be solved related to the design, construction and test of the proto type, the primary challenge is to end up with a system that is commercially competitive.

Design and construction of prototype

The design of the turbines together with the bearing systems was fulfilled at the end of February. The conceptual design gave adequate data to produce the 4 different turbine parts and further design of the turbine house, the bearing system, the spindle etc. all to manage high speed on the spindles.

The turbine parts were delivered in the start of April and installed together with the external components (evaporator, condensers, fans etc.). The turbine sealings/washers were later changed to manage adequate higher temperatures.

Through the sampling of the parts several changes were made e. g on the sealing on the connections between external parts for keeping a specific vacuum in the pipelines.

Testing

The external cooling and heating components have been designed, produced and mounted/installed for test purpose e. g. prepared for vacuum, setting up for optimal measurement of temperature, pressure etc.

Furthermore a PC and a data logger has been installed to make the measurement on different temperatures and pressures around the turbines and external components. The RPM-counter uses light to measure the speed — the power used to heat the water (in stead of a solar collector) is measured; PC- programs to calculate the performance on the proto type using test data (temp., pressure, RPM, power) are completed.

Test series on the proto type are going on in august 2008. Report on the test results will firstly be available on www. ac-sun. com.

Newest: Logged data from the first tests on the proto type gives positive results and confirms the function in the design. The expander delivers the compressor capacity as expected and used in the cooling process for air condition.

Plans for further testing

The proto type test is followed up by making 3-5 test units mounted with solar panels and placed around in the surroundings mainly in the southern Europe for optimal test conditions.

3. Conclusion

The AC-Sun system is a new concept for solar driven air-condition.

It is expected to have much higher efficiency than other soar driven systems as well as it is expected to be manufactured to much lower cost than other solar driven systems.

If expectations are met the system should have the potential to overcome market barriers for solar driven air-condition.

The challenge has been the design and construction of the steam driven turbine which rotate at very high speed.

For the moment (August 2008) a prototype had been constructed and is being tested. The testing until now has detected problems which have been solved. If the further testing in the coming months perform successful further prototypes will be produced and tested under real conditions in Southern Europe.

The AC-Sun system is reported and modelled as part of the Danish participation in IEA SHC Task 38 Solar Airconditioning and Refrigeration

References

[1] S. A.Klein, (1992-2008). EES (Engineering Equation Solver) PC-program, © F-Chart Software 2008.

[2] TRNSYS (TRaNsient SYstems Simulation program), © 2002 The Board of Regents of the University of Wisconsin System.