ANALYSIS OF A FUEL-SOLAR ASSISTED CENTRAL DUAL PURPOSE PLANT

A new arrangement for a central fuel fired solar assisted dual purpose plant (DPP) is presented and thermodynamically analyzed. The solar energy, collected at moderate temperatures, drives an open cycle LiBr-H2O absorption machine with a lp(s) turbine replacing the condenser and the evaporator used in such conventional heat pumps. In a DPP, this heat pump is connected upstream of the multistage flash (MSF) distillor where the lp(s) turbine receives the pass out steam assigned to the MSF and the steam leaves the heat pump generator is fed to the MSF. Whenever it is applied to a central desert steam power plant (DSPP), the heat pump is introduced upstream of the steam condenser. The same basic steam cycle is used in analyzing the combined arrangement for both the DPP and DSPP with a reheat being used to reduce the lp(s) corrosion problems. For a solar collecting temperature of 190-degrees-C for the DPP and 134-degrees-C for the DSPP the power output increased by 56 and 53% at an extra firing of 10.5 and 21% respectively. In the DPP, the combined arrangement can increase the water produced by four fold at the design power output or increasing the power output by 56% while maintaining the design water output.