New Design of Heat Recovery Steam Generator (HRSG) for Solar Thermal Hybrid Power Plants ISCCS (Integrated Solar Combined Cycle System)

摘要

One of the cheapest renewable energy productions is the hybrid solar thermal power plant. This is a thermal solar power production linked with a combined cycle process (CCP). The advantages are: Very high efficiencies due to high superheat and reheat temperatures. Extra energy extraction out of the flue gas, flue gas exit temperature drops. Rather low invest cost because of use of standard gas turbine and standard steam turbine. Very flexible operating modes, also in the night and with no sunshine. For high solar thermal power production linked into a combined cycle power plant a special HRSG design has to be taken in consideration to keep the invest and operation cost low. The optimisation has to be done with 3 mayor operation modes: Only gas turbine mode. With maximum solar thermal power. With maximum duct fire. For each case there would be an optimum size of superheaters, reheaters, evapoators and economizers, but there is only one size for all cases possible. This paper shows how to find an optimal solution and show the basic techniques are used to solve this problem. Each of the techniques is proven many times but rarely have all the techniques been used combined in a HRSG for a ISCCS. The design of the HRSG and the thermal power steam generator must been proven as reliable in all operation modes and be able to operate in a fast transient mode.