Browsing by Author "Marakkos, Costas"
Now showing 1 - 2 of 2
Results Per Page
Sort Options
- Finite dimensional models of the hydraulic hammer effect and solar tower controlPublication . Igreja, José; Marakkos, Costas; Lemos, JoãoThe occurrence of traveling shock waves associated to the sudden opening or closing of a valve, known as the hammer effect, is important from the perspective of control design because it imposes an upper bound constraint on the maximum bandwidth achievable for the controlled system. This article addresses the problem of characterizing hydraulic hammer effect of the heating fluid in a solar power tower. The transfer function that relates the increments of the pressure inside the pipe and the fluid velocity is computed, as well as its poles and zeros. In this way, it is possible to obtain finite dimensional linear approximations for this transfer function with a prescribed complexity. As an application, the traveling waves of pressure and velocity of a fluid used for temperature control in a typical solar tower circuit are simulated.
- The hydraulic hammer effect in solar tower fluid circuit temperature controllerPublication . Igreja, José; Marakkos, Costas; Lemos, Joao MThis article addresses the possible occurrence of hydraulic hammer effects in solar power towers and the limitations they impose on the response bandwidth of the control loop that governs the valve actuating on heating fluid flow. The partial differential equations that model the traveling waves associated to the hammer effect are solved with different methods. A finite dimensional approximation of the exact solution, by a transfer function with a finite number of poles is obtained. It is concluded that, for the speed of response of the temperature controller associated to the valve, there is no danger of inducing hydraulic hammer effects that can damage the equipment.