330 MW亚临界供热机组低压缸零出力改造方案的经济性分析

Economy Analysis for Zero-output Transform of Low Pressure Cylinder of 330 MW Subcritical Heating Unit

为提高电网对新能源的消纳空间,需对火电机组进行改造以提高其灵活性。针对某330 MW亚临界供热机组低压缸零出力改造方案,利用变工况热力计算方法对改造方案的调峰深度进行计算分析。首先通过对供热机组两种工况的校验计算,验证了变工况热力计算方法的准确性,然后对经过低压缸零出力改造后的供热机组进行计算分析。在不影响额定供热抽汽的前提下,通过与其他工况下的负荷率进行对比,分析低压缸零出力改造方案对机组灵活性的提升。结果表明,该方案能使该机组负荷率降低到40%以下,位于第2档的补偿电价区间,满足现有的国家调峰政策要求。

To improve capacity of the power grid to absorb new energy, it is necessary to transform the thermal power unit to improve the flexibility. Aiming at a transform scheme for zero-output of low pressure cylinder of one 330 MW subcritical heating unit, this paper makes use of variable wording condition calculation method to analyze peak regulation depth of the transform scheme. By checking calculation for two wording conditions of the heating unit, it verifies accuracy of variable wording condition calculation method, and then it makes calculation and analysis for the heating unit after transform of zero-output of the low pressure cylinder. With no effect to rated heat supply and steam extracted, it makes comparison of load rates under different working conditions and analyzes effect of the zero-output transform scheme on promoting flexibility of the unit. The result indicates that this scheme can reduce load rate of the unit less than 40%, which is located in the compensation price range of the second stage and meets the requirements of the existing national peak shaving policy.