Analysis on wind power accommodation ability and coal consumption of heat–power decoupling technologies for CHP units

Abstract

The traditional combined heat and power (CHP) units restrict the operational flexibility and causes serious wind power curtailment. To study the wind power accommodation ability and coal consumption, a new method is proposed to calculate the heat–power characteristic of CHP units with different decoupling technologies. A series of mathematical models are established to quantitatively compare the wind power accommodation ability, coal consumption and pollutant emissions. The results show that the minimum electric power of traditional CHP units can be decreased equipped with a heat storage tank only under high heating load but it can be decreased when installed with an electric boiler and high pressure-low pressure (HP-LP) bypass heating under any heating load. With the increase of heating load, the wind power accommodation ability of CHP units with three typical decoupling technologies decreases. The amount of coal consumption of CHP units with HP-LP bypass heating saves twice more than with electric boiler, and saves 30 times more than with heat storage tank. Furthermore, HP-LP bypass heating technology can reduce pollutant emissions efficiently. In engineering practice, the optimal decoupling technology should consider the CHP unit self condition, wind power load, electric power generation and heating demands.