火电厂保温超低散热技术研究

Research on Ultra-Low Heat Dissipation Technology in Thermal Power Plants

为减少火电厂管道散热损失,节能降耗,采用保温超低散热技术,计算主蒸汽管道保温结构外表面温度从50℃到30℃,保温厚度、减少的热量损失、投资增加值及投资回收年限,并以山东某电厂(2×1 000 MW)新建工程为例,比较了主蒸汽管道保温结构外表面温度为45℃和50℃时的保温投资,结果表明,将主蒸汽管道保温结构外表面温度从50℃降到45℃时,保温层材料体积将增加,增加投资约30万元,但可减少锅炉出口至汽轮机入口之间主蒸汽和再热蒸汽热段温降1～2℃,降低机组煤耗约0.6 g/(kW·h),为电厂带来可观的经济效益。

In order to reduce the heat dissipation losses and save more energy in thermal power plants,by adopting the ultra-low heat dissipation technology,this paper calculates the insulation thickness,heat dissipation reduction,investment increase and investment recovery years of the main steam pipe with the external surface temperatures of insulation structure ranging from 50℃to 30℃.By taking the newly-built power plant(2×1 000 MW)in Shandong Province for example,the investment in heat preservation is compared with respect to external surface temperatures of main steam pipe of insulation structure at 45℃and 50℃.The results show that when the external surface temperature of the insulation structure declines from 50℃to 45℃,the total volume of the insulation materials will grow,which will cause the increase of the investment by 300 thousand RMB yuan.Nevertheless,the temperature drop at the main steam cycle and the hot reheat steam cycle between the boiler outlet and the steam turbine inlet is reduced by 1 to 2℃and thus the unit coal consumption is lessened by about 0.6 g/(kW·h).Therefore,substantial economic benefits is achieved for the power plants.