A 150MW solar thermal power station heats molten salt using concentrated solar radiation (via heliostats) and then uses that hot liquid salt to generate steam. The steam is used to generate electricity via a power iurbine. The hot molten salt is stored in a very large and well-insulated storage tank so that electricity can pe generated during the night time. - The efficiency of the solar collector system (i.e. heliostat) at converting solar radiation into heat is 3%. Typical solar radiation values in the North QLD region are 900W/m2 over a 10 hour period. - The molten salt ( 60% sodium nitrate and 40% potassium nitrate) leaves the cold salt storage tank and is heated to 565C in the solar concentrator. The hot molten salt passes through a hot salt storage tank before entering a steam generator (i.e. heat exchanger). After the steam generator the molten salt at 288C returns to the cold salt storage tank. Assume the salt remains at atmospheric pressure throughout. - In the steam generator heat is exchanged between molten salt and steam. Steam leaves the steam generator at 550C and 180 bar. Water entering the steam generator is saturated water at 110C. - Steam leaving the steam generator enters the turbine where electricity is generated, and leaves as wet steam at 110C with a liquid quality of 12%. The turbine operates with 38.5% efficiency. - The wet steam leaving the turbine is fully condensed to saturated liquid at 110C before returning to the steam generator. a) What is the specific heat capacity of the molten salt ? Provide a complete reference. b) Draw a diagram of this process, fully labelling each unit and all streams. c) Provide enthalpy values (in kJ/kg ) for all of the streams in the process. Clearly define the reference states. d) If the plant is run during daylight hours only, calculate the molten salt flow rate and heliostat surface area required to produce 150MW. e) If the plant is used to produce 150MW during night time hours only, what heliostat surface area is required and what size of hot molten salt storage tank is required. f) Discuss and compare the life cycle impacts of solar thermal and solar PV electricity generation systems. A 150MW solar thermal power station heats molten salt using concentrated solar radiation (via heliostats) and then uses that hot liquid salt to generate steam. The steam is used to generate electricity via a power iurbine. The hot molten salt is stored in a very large and well-insulated storage tank so that electricity can pe generated during the night time. - The efficiency of the solar collector system (i.e. heliostat) at converting solar radiation into heat is 3%. Typical solar radiation values in the North QLD region are 900W/m2 over a 10 hour period. - The molten salt ( 60% sodium nitrate and 40% potassium nitrate) leaves the cold salt storage tank and is heated to 565C in the solar concentrator. The hot molten salt passes through a hot salt storage tank before entering a steam generator (i.e. heat exchanger). After the steam generator the molten salt at 288C returns to the cold salt storage tank. Assume the salt remains at atmospheric pressure throughout. - In the steam generator heat is exchanged between molten salt and steam. Steam leaves the steam generator at 550C and 180 bar. Water entering the steam generator is saturated water at 110C. - Steam leaving the steam generator enters the turbine where electricity is generated, and leaves as wet steam at 110C with a liquid quality of 12%. The turbine operates with 38.5% efficiency. - The wet steam leaving the turbine is fully condensed to saturated liquid at 110C before returning to the steam generator. a) What is the specific heat capacity of the molten salt ? Provide a complete reference. b) Draw a diagram of this process, fully labelling each unit and all streams. c) Provide enthalpy values (in kJ/kg ) for all of the streams in the process. Clearly define the reference states. d) If the plant is run during daylight hours only, calculate the molten salt flow rate and heliostat surface area required to produce 150MW. e) If the plant is used to produce 150MW during night time hours only, what heliostat surface area is required and what size of hot molten salt storage tank is required. f) Discuss and compare the life cycle impacts of solar thermal and solar PV electricity generation systems