 |
|
 |
|
 |
|
 |
|
 |
|
 |
|
 |
|
 |
|
 |
|
 |
|
 |
|
 |
|
 |
|
 |
|
 |
|
(c) RENOVETEC 2010. All right reserved
|
|
|
|
|
|
 |
|
STEAM GENERATOR SYSTEM
|
Español
Rankine cycle in which solar thermal power
plants are based, can be seen in Figure 1. It is cycle consists of superheat,
reheat and regeneration. Efficiency around 40% is obtained.
Solar thermal
power plants CCP use two pressure levels: 103 bar and 18 bar (approximate
values). Analyzing Rankine cycle, it can be noticed that during the steam
expansion inside the high pressure turbine, at one particular moment, saturation
conditions are reached and water droplets appear in the steam. To prevent blades
erosion caused by these droplets (Which behave like stones hitting the blades)
it is preferred to remove the steam, reheat and expand it again at a special low
pressure turbine. As shown in figure 2, the energy balance of a solar thermal
power plant at 100% load
Taking into account the Rankine cycle graph
shown in Figure 3, the steam generator system of a solar thermal power plant
will consist of the following equipment:
-Economiser or preheater, based on raising water
temperature from approximately 245 ° C to about 310 ° C, very close to the
evaporation temperature (around 314 º C to 104 bars of pressure).
-
Evaporator. It is simply based on
changing the water state to produce saturated steam at 314 º C and 104 bar
pressure. Remember that these values are reached when the plant is at 100% load,
and that values change appreciably at other loads.
- Superheater. It is the equipment responsible
for increasing steam temperature to about 380ºC.
- Reheater. It is located between the high
pressure turbine output and the low pressure turbine input. Temperature is
raised from 200ºC to 380ºC. This large thermal difference between the input and
the output of fluids and the fact that solar thermal power plants start and stop
everyday, have caused serious problems in the equipment operation. Reheater’s
new designs are more adapted to these hard operation conditions. These new
designs have superseded initial disadvantages. However, it should make sure that
the chosen heat exchanger has really superseded these serious problems.
|
NEW BOOK NOW
AVAILABLE
|
CAREERS
 |
| If you want
to work in solar thermal world, or you are a company related to the
development,
construction,starting up , operation and/or maintenance of solar
thermal power plants, send your CV (candidates) or your job vacancies
(businesses) to: |
|
|
|
|
|
|
(c) RENOVETEC 2010. All right reserved
|
|
|
