低压省煤器系统的传递特性

Exergy Transfer Characteristics of the Low Pressure Economizer System

依据传递原理建立了锅炉低压省煤器传递分析模型。根据传递评价准则,定义了传递过程、流密度的概念。结合等效焓降原理,推导出串、并联低压省煤器系统的焓降、流密度计算式,并以某国产680 MW发电机组为例,进行了传计算。结果表明,排烟温度降至95℃,供电煤耗降低了1.75g/k W·h,节能效果明显。低压省煤器回水接入系统的位置对节能影响较大,为低压省煤器优化提供借鉴。

Based on the exergy transfer principle, the exergy transfer analysis model with low pressure is estab- lished, which is more economical. In the light of engineering exergy transfer evaluation criterion, the process of ex- ergy transferring and its flux are given. Based on the equivalent enthalpy drop method, the formula for the enthalpy drop and the exergy flux had been deduced. An exergy transfer analysis for a 680MW unit is made as an example, and the results show that, the exhaust gas temperature can reach 95℃ with the unit coat consumption rate reduced by 1.75 g/kwh, the goal of energy saving had been achieved and it provides references for further improvement of the system.