The HTF typically arrives at the heat exchanger at 70 �C and returns to the circulating pump at 50 �C . Pumping typically starts at about 50 �C and increases as the sun rises until equilibrium is reached.
32.
Circulating pumps are often used to circulate domestic hot water so that a faucet will provide hot water instantly upon demand, or ( more conserving of energy ) a short time after a user's request for hot water.
33.
:A packaged set of circulating pumps mounted in a cabinet, which often includes valves and ports for flushing / purging, antifreeze charging ( if used ), and loop pressurization ( if a pressurized flow center is used ).
34.
In most HVAC systems, the use of sacrificial anodes and cathodes is not an option, as they would need to be applied within the plumbing of the system and, over time, would corrode and release particles that could cause potential mechanical damage to circulating pumps, heat exchangers, etc.
35.
The fluid circuit, as well as containing the circulating pump, will also contain an expansion vessel, to accommodate changes in fluid pressure; a fill device, to ensure the system remains charged; controls to bypass and shut down the system when not required, and various other safety devices and ancillaries.
36.
In parabolic trough plants, copper is specified in the solar collector field ( power cables, signals, earthing, electrical motors ); steam cycle ( water pumps, condenser fans, cabling to consumption points, control signal and sensors, motors ), electricity generators ( alternator, transformer ), and storage systems ( circulating pumps, cabling to consumption points ).
37.
Copper is required in the heliostat field ( power cables, signal, earthing, motors ), receiver ( trace heating, signal cables ), storage system ( circulating pumps, cabling to consumption points ), electricity generation ( alternator, transformer ), steam cycle ( water pumps, condenser fans ), cabling to consumption points, control signal and sensors, and motors.
