Thermal Analysis Of Solar Power Plants

Thermal solar power plants are similar to the conventional ones with the exception that a field of concentrating solar collectors replaces the conventional steam boiler. In hybrid plants, a conventional boiler is also present, operating on conventional fuel, usually natural gas, whenever there is a need. Therefore, the thermal analysis of solar power plants is similar to that of any other plant and the same thermodynamic relations are applied. The analysis is greatly facilitated by drafting the cycle on a T-s diagram. In these cases, the inefficiencies of pump and steam turbine should be considered. In this section, the equations of the basic Rankine power cycle are given and two of the more practical cycles, the reheat and the regenerative Rankine cycles, are analyzed through two examples. To solve the problems of these cycles, steam tables are required. Alternatively, the curve fits shown in Appendix 5 can be used. The problems that follow were solved by using steam tables.

The basic Rankine cycle is shown in Figure 10.9a and its T-s diagram in Figure 10.9b.

Boiler

3

Pump

Condenser

Condenser

Turbine

FIGURE 10.9 Basic Rankine power plant cycle. (a) Basic Rankine cycle schematic. (b) T-s diagram.

FIGURE 10.9 Basic Rankine power plant cycle. (a) Basic Rankine cycle schematic. (b) T-s diagram.

As can be seen in Figure 10.9, the actual pumping process is 1-2' and the actual turbine expansion process is 3-4'. The various parameters are as follows: Turbine efficiency,

Pump efficiency,

Net work output,

Heat input,

Pump work,

npump

Net Analysis Solar Power Plant
(a)

FIGURE 10.10 Reheat Rankine power plant cycle. (a) Reheat Rankine cycle schematic. (b) T-s diagram.

FIGURE 10.10 Reheat Rankine power plant cycle. (a) Reheat Rankine cycle schematic. (b) T-s diagram.

Cycle efficiency,

Solar Power

Solar Power

Start Saving On Your Electricity Bills Using The Power of the Sun And Other Natural Resources!

Get My Free Ebook


Post a comment