Parabolic trough systems use curved mirrors to focus the sun’s energy onto a receiver tube that runs down the center of a trough.
In the receiver tube, a high-temperature heat transfer fluid (such as a synthetic oil) absorbs the sun’s energy, reaching temperatures of 750°F or higher, and passes through a heat exchanger to heat water and produce steam.
The steam drives a conventional steam turbine power system to generate electricity.
A typical solar collector field contains hundreds of parallel rows of troughs connected as a series of loops, which are placed on a north-south axis so the troughs can track the sun from east to west.
Individual collector modules are typically 15-20 feet tall and 300-450 feet long.
Parabolic Through Diagram
Parabolic trough power plants are the most mature of the CSP technologies, with over 4000 MW in operation worldwide and a history of commercial plant operation dating to the early 1980s (SolarPACES.org).
Trough power plants have large arrays of solar collectors that feature mirrors curved in the shape of a parabola to focus sunlight onto a linear pipe . An HTF, often synthetic oil, flows through the receiver pipe and is heated by the absorbed sunlight.
This hot HTF is used to generate steam that turns a conventional steam turbine/generator to produce electricity.
The spent steam from the turbine is condensed into water and recirculated by feedwater pumps to be transformed back into high-pressure steam.
Wet, dry, or hybrid cooling can be used to cool and condense the spent steam. A parabolic trough plant is composed of several subsystems: solar collector field, receiver and associated HTF system, power block, thermal storage (optional), fossil-fired backup (optional), and necessary ancillary facilities, TES is provided by exchanging heat from the oil HTF to a molten salt, which is cheaper than oil and exhibits negligible vapor pressure even when heated to several hundred degrees.
Soljex redesign the Parabolic Trough network to utilize the heat exchanging system for water desalinations,