Annual Performance Simulation of a Solar Cogeneration Plant with Sensible Heat Storage to Provide Electricity Demand for a Small Community: A Transient Model

Abstract

I n this paper, a solar-driven power system as a means of meeting electricity demand in a small community has been investigated in terms of its transient performance on an annual basis. Using a sensible heat storage unit, the heat collected by evacuated flat plate collectors EFP can be stored and used at other times to feed an organic Rankine cycle ORC . The storage unit is analysed using a one-dimensional temperature distribution model including heat loss to the ambient. The stored heat in the unit makes it possible to produce electricity at night. In order to meet the electricity demand in all seasons, evaporation temperature is controlled by the present model via adjusting the water mass flow rate of the heat source. Solar ORC using EFP collectors is a promising technology but dynamic simulation on its annual performance has not been conducted yet. Investigation of the daily performance with consideration of transient behaviour of the components is the main aim of the study. The system performance is evaluated for different seasonal weather conditions. An 8-kW expander output is desired for the peak period which is in the evening for a small community, when sufficient solar irradiance is available. The system also operates in combined heat and power mode during the winter period to supply heat for space heating purpose. Results show that 23296.8 kWh electricity is produced considering the demand pattern during the year and 19344.7 kWh heat can be used for heating for the selected four months

Keywords

• Solar ORC,Cogeneration,Heat storage,Annual transient simulation

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