A novel Carnot-based cycle for ocean thermal energy conversion
- 標題
- A novel Carnot-based cycle for ocean thermal energy conversion
- 作者
- Hamza Semmari, Driss Stitou, Sylvain Mauran
- 文件屬性
- 國外期刊
- 知識分類
- 能源利用
- 出版年
- 2012
- 刊名
- Energy
- 關鍵字
- Carnot engine; OTEC; Liquid piston; Thermo-hydraulic process
- 點閱數
- 2534
摘要
A thermodynamic engine cycle can be implemented by exploiting the temperature difference existing between the warm surface seawater and cold deep seawater. It employs a working fluid that evaporates by warm seawater, produces work in an expander device, such as a gas turbine and finally condenses by cold deep seawater. A new Carnot-based cycle for OTEC applications, called CAPILI cycle is presented. In this new engine cycle, work is produced by the movement of an inert liquid through a hydraulic turbine. This inert liquid characterized by a very low saturation pressure and immiscibility with the working fluid, acts as a liquid piston that moves alternately between two insulated cylinders. The insulated cylinders are connected alternately to an evaporator and a condenser, each of them operates at different pressure and temperature levels. A performance study which consists in a steady state energy balance is realised first to select the most suitable working fluid for this specific application. It was found that the best fluid is the HFC refrigerant R134a. A dynamic modelling based on the concept of equivalent Gibbs system is carried out to appreciate the dynamic behaviour and the performances of this new thermal conversion process.