Construction of a Static Model for Power Generation of OTEC Plant Using Uehara Cycle Based on Experimental Data

This paper considers the construction of a static model for the power generation of an ocean thermal energy conversion (OTEC) plant using Uehara cycle. The model is constructed based on experimental data obtained from an actual experimental OTEC plant. In this paper, two kinds of static models are proposed. In both models, the relations among significant quantities are represented by polynomials. The polynomials are determined via least squares for experimental data, and the orders of polynomial which minimize the integral of absolute error between experimental data and simulation results of power generation are adopted. The usefulness and limitations of the proposed models are evaluated by simulation results

Construction of a state-space model with multiple flow rate inputs for an OTEC plant using Rankine cycle

Recently, the importance of sustainable energy using renewable resources has been recognized. As one of the sustainable energy resources, ocean thermal energy conversion (OTEC) is important for the development of a next-generation energy source. This paper proposes a method to construct a state-space model for an OTEC plant using the Rankine cycle. The state-space model is constructed based on a linear approximation of a simple dynamic model. The flow rates of warm seawater, cold seawater, and working fluid are considered as inputs to the model, and the power output is selected as the output of the model. The state-space model, described as a time-invariant system, is derived numerically. The constructed model is evaluated through numerical simulations of the step response; the power generation control is verified using proportional integral controllers, and the advantage as a state-space model is verified using a linear quadratic regulator. The simulation results demonstrate the effectiveness and limitation of the proposed model. Because the simple dynamic model to be approximated is constructed based on the physical laws, various kinds of state-space models corresponding to the physical parameters can be obtained easily