Impact Of Central Tower Receiver Technology On Production Of Energy By Using Molten Salts As Heat Transfer Fluid

In this study,two variations of concentrated solar power plant(CSP)are proposed one with active storage system and other using latent heat storage.In first design molten salt is heated to 550 oC at central tower receiver(CTR)and stored in hot tank.When power is required hot molten salt is pumped towards steam generator(turbine)and then back to cold tank.This pilot project is proposed,have capacity of 20 MW and will have up to 9 hours of autonomy.A newly developed salt is used for heat transfer and storage.This salt consists of Ca(NO3)2,KNO3,NaNO3.Salt have advantage of low cost and holds good properties.Its melting point is 140 oC and is thermally stable upto 550 oc.Newly developed Phase change material NaCl+Na2 Co3 is used for designing latent heat storage,with its high melting point of 630 oC and respectable phase change enthalpy of311J/g,this system can achieve much higher efficiency.Heat Transfer Fluid will be required to transfer energy between storage and steam generator as well as between tank and receiver.Detailed mathematical modeling is done for major components of the power plants including Heliostats,Central Tower receiver,hot salt storage tank,cold tank,turbine and electric generator.Finally simulations are performed to simulate the performance of power plant in realistic conditions.First energy received on the tower receiver is calculated on the basis of every hour throughout the year based on the position of sun and heliostats.Then each subsystem is simulated in MATLAB according to its thermodynamics model developed earlier.Plant performs well and as simulation suggests will be able to operate when solar irradiations will be available and during which peak demand exist in summer.2million kg of salt gives us capability to operate the plant for 4.5 hours or more in winter and up to 9 hours every day in summer at any time of day.For same conditions Latent heat storage design will give us up to 24 MW of power due to high temperature storage enabling the use of high efficiency multistage turbine.