生物质有机朗肯循环热电联供系统的热经济分析

THERMO-ECONOMIC ANALYSIS OF BIOMASS-FIRED ORGANIC RANKINE CYCLE COMBINED HEAT AND POWER SYSTEM

构建生物质直燃有机朗肯循环热电联供系统,定义供暖系数表征输入供暖系统和有机朗肯循环的能量分配关系,通过热力学分析和经济评价优化系统参数。研究结果表明:升高蒸发温度,供暖系数减小;供热水/回水温度较高时,系统有较大供暖系数、效率和热效率,而发电效率、一次能源节约比和系统总投资较小;以动态回收年限或投资利润率为目标优化的蒸发温度小于以系统运行年限利润总额现值为目标确定的最优值。所研究的生物质有机朗肯循环热电联供系统的一次能源节约比为5.91%~12.78%,投资利润率为3.25~3.88,系统能源利用率较高且热经济效益显著。

A novel biomass-fired organic Rankine cycle(ORC)combined with heat and power(CHP)system is developed,in which the supplying heating ratio is defined to characterize the energy distribution relationship between the supplying heat system and ORC.System parameters are optimized through thermodynamic analysis and economic assessment. Results show that the temperature of pressurized hot water generated from biomass boiler is improved with increasing evaporation temperature. The biomass-fired ORC-CHP system achieves higher supplying heating ratio,exergy efficiency and thermal efficiency with higher temperature of supplying heat hot water,while presenting lower power efficiency,primary energy saving ratio and system total investment,in which the optimized evaporation temperature considering dynamic payback period and profit ratio of investment(PRI)is lower than the counterpart achieved by net present value. The primary energy saving ratio(PESR)of cogeneration system varies from 5.91%-12.78%,while the PRI changing between 3.25 and 3.88. As a result,the studied bioenergy system is thermodynamically feasible and economically attractive.