Power conversion unit

PCU 35 called aggregate includes the Stirling engine with generator and an external heat exchanger – receiver. The thermal receiver is a set of thin tubes with a working gas (Helium). The thermal receiver is the interface for heat transfer from concentrating reflected radiation from solar concentrator (dish) into the hot upper side of Stirling engine.

The receiver which is placed on a cavity of PCU absorbs the incoming concentrated thermal energy (700°C – 800°C). 
Absorbed heat energy in working gas (~650°C) is transferred into mechanical energy in expansion cylinder. 
Installed crank drive provides rotating driving moment (1500 RPM) for generator which generates clean electricity (400 V, 50Hz, 3 phases). 
Maximum operating RPM are 1800 RPM (60 Hz). 
The cooling of the PCU and Stirling engine is managed by a closed loop cooling system with blower and radiators and therefore no water is consumed during common operation. 
Cooling liquid temperature at engine input is 45°C (antifreeze fluid). 
Water is used only for cleaning purposes of the concentrator’s mirrors and therefore the water consumption is extremely low compared to other CST, ST and CSP technologies.

The remaining integral parts of aggregate are control system and switchboard with measurement and regulation system, auxiliary pressure vessel with Helium and heat resistant ceramic protective shield.

The quality of production and assembly processes and their continuous quality control are fundamental for all parts of PCU and Stirling engine. Quality assessment is a permanent process, which is being continuously developed and improved in compliance with European Standards (EN ISO 9001, EN ISO 14001, EN ISO 3834, etc.).