加装低压省煤器对汽轮机排汽量的影响研究

为研究低压省煤器吸收的排烟余热的有效利用水平，基于等效焓降法的基本原理，建立了汽轮机低压加热系统中凝结水抽出与引入对其排汽量影响的通用计算模型，进而推导出低压省煤器在各种连接方式下投入运行后对汽轮机排汽量影响的通用计算模型。以某国产330 MW机组为例，利用所提出的计算模型得出两种不同工况下汽轮机排汽量和排汽损失的增加值，结果表明，低压省煤器吸收的排烟余热能用于汽轮机做功的仅为10%左右，其余热量最终都进入冷源损失。

Study on the Effects of Low Pressure Economizer on Turbine Exhaust Volume

In order to evaluate the effectiveness of utilizing the heat absorbed by the low-pressure economizer, based on the fundamental principles of the equivalent enthalpy drop method, a general computation model is established for the influence of extraction and injection of the condensate in the low-pressure heating system on the exhaust volume of the steam turbine. Then, a general model is derived to compute the influence of the low-pressure economizer on the steam turbine exhaust volume when operated under various connection modes. Taking a domestic 330 MW unit as an example, using the computation model proposed in this paper, the increments of the steam exhaust volume and exhaust losses under two different operating conditions are obtained respectively, which shows that only about 10% of the thermal energy absorbed in the low-pressure economizer is reused by the steam turbine to produce power, while the rest of the heat eventually becomes part of cold source loss.