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THERMAL_BALANCE library examples
Solar plant with direct supply to the cycle and accumulator load
This model represents solar plant operation with direct supply to the cycle and loading the accumulators with excess energy, the cycle of which is maintained at 100% power by loading the accumulators with the excess energy supplied by the receiver.
Accumulator drain flow returns to the cycle through the drain line to heat "H3".
Controllers "PID" and "HC" control the pressure levels in the accumulators by actuating the "DA" splits as the associated load sequence controllers.
Establishing the energy transmitted by the receiver as a function time the cycle is maintained at 100%, supplying excess energy to the accumulators to bring them to the pressure and level conditions required to enter into operation. These conditions have been established at 42 psia and 2.69 metres.
The initial conditions of the accumulators are a pressure of 21.995 psia and a steam quality of 0.00237.
The level controller sequentially supplies flow to each accumulator until the desired level is reached and then the pressure is controlled by opening the drain valve.
When the conditions in the first accumulator are established, the excess flow from the cycle is diverted to the second accumulator and so on, until all the accumulators reach operating conditions.
At the price of losing some precision, a level controller with a small differential factor has been introduced to reduce drain valve operation fatigue.
The following plots illustrate the evolution of the energy transmitted by the receiver, the inlet flow to the accumulators, the operating pressure in the accumulators, the level in the accumulators, the total flows to the cycle and accumulators, the flows to the accumulators and receiver, makeup flows, and extraction flows.
