三重循环构成的太阳能热发电系统

A New Solar Thermal Power System Using Triple Cycle

本文提出了一种由太阳能燃气轮机循环、朗肯循环、卡林那循环组成的联合循环发电系统,并对其热力性能进行了分析,塔式太阳能接收器将压缩空气加热至1000℃或更高用以驱动燃气轮机做功.燃气轮机出口的中温烟气用于驱动背压式汽轮机,低温烟气和背压式汽轮机的排气共同驱动一个卡林那循环,结果表明,当燃气轮机入口温度为1000℃时,该系统的效率和太阳能热发电效率分别可达到27%和25.7%.朗肯底循环和卡林那底循环使该系统能在低辐照时发电.该系统的提出,为提高太阳能热发电系统的太阳能热发电效率提供了一种方法,并且对太阳能热发电耗水量大的问题提供了一个解决途径.

This paper proposed a new solar-driven triple cycle integrating the solar gas turbine top cycle, steam Rankine cycle and the Kalina bottom cycle. On the top cycle of the proposed system, the compressed air is heated to 1000℃ or higher at the solar tower receiver and is used to drive gas turbine for electricity. A Rankine cycle with a back pressure steam turbine was utilized to recovery the waste heat from the gas turbine to generate electricity through the steam turbine. The bottomcycle is a Kalina cycle comprising another back pressure turbine and using ammonia-water mixture as a working fluid. After driving the steam Rankine cycle, flue gas from the gas turbine sequentially heating the ammonia-water mixture to produce power. As a result, the peak exergy efficiency and solar-to-electric efficiency of the proposed system are separately 270/o and 25.7% at a gas turbine inlet temperature of 1000℃. A new operation strategy is presented to generate electricity during low isolation period without the backup of fossil fuel. The results obtained in the current study provide an approach to improve solar-to-electric efficiency and offer a potential to conserve water for solar thermal Dower plants in arid area.