Welcome to Geothermal Power Plants Modeling 301: Dynamics Simulation. If you read my blog 101 which is about rigorous modeling and my blog 201 which is about fast rating and optimization, you notice both 101 and 201 are about steady state simulation. In 301, we are going to explore the dynamics simulation which can simulate the power plant performance real time with variable changes, such as dry bulb. In this blog, you will be able to see the dry bulb changes versus time and the power plant output versus time.
In this dynamics model, we have the vaporizer, the expander, the recuperator, the air cooled condenser, the receiver, the feed pump and the valve-100 to control the liquid level in the receiever.
The vaporizer is split into 5 sections to improve the calculation accuracy given a fixed UA.
The expander efficiency is fixed since there is no good way to predict the exapnder efficiency in the dynamics simulation mode.
The recuperator is modeled with fixed UA
The ACC is split into 2 segments to improve the calculation accuracy given a fixed UA.
The reciever is modeled with 100 m3 and the liquid level is about 50%.
The feed pump is rated based on the performance curves.
The valve VLV-100 is used to control the liquid level in the receiver to be constant at about 50%.
There are several events scheduled in this dynamics simulation.
At minute 5, the dry bulb temperature will be increased by 2 C, based on the current dry bulb value which is 10 C. At minute 10, the dry bulb is increased by 2 C again. At minute 35, the dry bulb is decreased by 2 C and finally at minute 40, the dry bulb is decreased by 3 C.
Let us start the dynamics simulation. As you can see in the chart, the dry bulb temperature starts to increase per the schedule events. It first rises and then it drops back to 10 C. The red line represents the power output of the plant and it responses to the dry bulb temperature. When the dry bulb rises, the power output drops. And when the dry bulb decreases, the power output increases.
With dynamics simulation, user can even simulate the power plant in a year time line to get the true annual output of the plants.
Thanks for reading the Geothermal Power Plants Modeling series. 101 is about rigorous rating to give the users great confidence to guarantee plant output. 201 is about fast rating and optimization to have the most output given any operating conditions. 301 is about dynamics simulation to give you a deep insight how the plant reacts to variable change, such as ambient temperature. Thanks again for watching the video. It is brought to you by Guofu Chen
