抽凝机组耦合热电转换辅助调峰系统参数设计

  目的  为适应新能源电力并网需求，原有抽凝热电联产机组深度调峰供热改造已为重要途径之一。现有包括电热泵和电锅炉在内的热电转换装置为辅助火电机组调峰提供了潜在途径。  方法  以350 MW抽凝机组为例，建立了以热电转换装置辅助调峰参数优化模型，重点分析了热电转换设备参数对深度调峰性能的影响；其次，分别对比了电热泵和蓄热电锅炉两种典型热电转换系统在不同装置容量、不同放热速率下的调峰深度；最后，介绍了300 MW燃煤机组的煤耗率与污染物排放水平，指出本系统的节能效益，并给出热电转换装置的最优参数。  结果  结果显示:当电热泵的热功率为100 MW、放热速率与热功率相匹配也为100 MW时，机组的调峰深度达到最大值，为73 MW左右；当蓄热式电锅炉的电功率为45 MW、放热速率为100 MW时，机组的调峰深度达到最大值，为70.05 MW。蓄热式电锅炉的储热量在24 h中内略有增加，净储热量的数值为967.5 kWh。  结论  功率和放热速率是衡量热电转换装置辅助机组调峰能力的重要参数，且二者之间要有一定程度上的匹配性，针对不同情景灵活匹配热电转换装置的类型与参数可大幅提升机组的调峰深度。

Parameter Design of Coupled Thermoelectric Conversion Auxiliary Peak Shaving System for Condensing Unit

  Introduction  In order to meet the demand for new energy power grid connection, the deep peak-shaving heat supply transformation of the original extraction and condensing cogeneration unit has become one of the important ways. Existing thermoelectric conversion devices, including thermoelectric pumps and electric boilers, provide a possible way to assist thermal power units in peak shaving.   Method  Taking a 350 MW extraction condensing unit as an example, an optimization model for peak shaving parameters assisted by a thermoelectric conversion device was established, and the influence of thermoelectric conversion equipment parameters on the deep peak shaving performance was analyzed. Secondly, the peak shaving depths of two typical thermoelectric conversion systems of electric heat pump and thermal storage electric boiler under different device capacities and different heat release rates were compared, respectively. Finally, the coal consumption rate and pollutant emission level of the 300 MW coal-fired unit were introduced, the energy-saving benefit of the system was pointed out, and the optimal parameters of the thermoelectric conversion device were given.   Result  The results show that when the thermal power of the electric heat pump is 100 MW and the heat release rate is also 100 MW, the peak shaving depth of the unit reaches the maximum value, which is about 73 MW. When the electric power of the regenerative electric boiler is 45 MW, and the heat release rate is 100 MW, the peak-shaving depth of the unit reaches the maximum value of 70.05 MW. The heat storage capacity of the regenerative electric boiler increases slightly within 24 h, and the net heat storage value is 967.5 kWh.   Conclusion  Power and heat release rate are important parameters to measure the peak shaving capacity of auxiliary units of thermoelectric conversion devices, and there must be a certain degree of matching between the two. Flexible matching of the type and parameters of the thermoelectric conversion device for different scenarios can greatly improve the peak shaving depth of the unit.