本文针对某地区电网进行了研究，该电网是典型的外受端电网，高外受电比给调度带来了很大的局限性；而内受电又以燃气机组供电为主，在实际运行中表现出了与传统电网不同的特性；此外，还面临着沉重的压减电量的任务。目前，该电网在机组负荷率、启停安排、备用容量等方面仍存在着一些不足。为了进一步改善该区域电网的运行状况，本文针对电网结构和电力供需矛盾进行了调研，针对电网调度的策略进行了研究和优化。通过对电网的调研，明确了不同季节电网调度所面临的主要矛盾，在供热季是机组热电联供特点与电网需求间的矛盾，在夏季是调峰需求和燃机运行特性间的矛盾，在检修季则是检修安排和电网无功功率支撑间的矛盾。燃气机组在运行过程中的主要问题有负荷率偏低，负荷波动大，启停次数过多，备用容量不足，总电量分配缺乏宏观调控等。通过对调度策略的研究和优化，问题的目标函数被明确为负荷率、运行稳定性、启停次数、停机天数、备用容量5个方面，约束条件被明确为电/热量指标、机组额定负荷、年度计划发电量、温度约束、供热约束、检修计划、其他约束等7个方面。建立了调度算法的数学模型，并利用MATLAB平台的编程实现了热电计划安排的程序计算和快速输出。通过对2015年实际运行情况的复现，验证了算法的可行性。优化后，各机组各季度的平均负荷率相较于优化前更加接近理想区间；负荷率波动更加平稳；启停次数更少；每次停机的时长基本控制在2~7天内。考虑到夏季调峰需求和温度约束之间的矛盾给电网运行带来的压力，本文还通过建立Maisotsenko循环的计算模型研究了通过进气冷却提高燃机在高温下的出力的可行性。出力提高的主要原因是进口温度的下降和工质质量流量的增加，降低冷却器压损和减少冷却器功耗有助于更好地发挥其作用。无进气冷却、直接进气冷却、间接进气冷却分别适用于相对湿度从高到低的情况。
The development of social economy is putting higher and higher requirement of quality and environmental protection on the regional energy supply. Gas - steam combined cycle units, with quick start - stop speed and advantages of environmental protection, is playing more and more important role in the energy structure. Compared with coal unit, gas unit has more quick speed of start - stop and load regulation, to meet the demand of power grid frequency control. The efficiency of combined heat power plant with gas turbine is very high. In addition, compared with coal, the clean fuel determines its irreplaceable advantages of environmental protection. However, due to the restricted supply of natural gas, the introduction of clean and renewable wind energy from the northwest, heating subsidies, and other policies of energy, the area under investigation gradually formed a unique way of power grid operation. It has become the main task faced by scheduling worker, that how to give consideration to both safety and economy in the process of power grid operation, and the characteristic of gas unit.In order to fully grasp the present situation of the scheduling work, and indicate the direction for further optimization, recent situation of power grid scheduling is given statistics and analysis, based on the detailed investigation in the area power grid structure and units characteristics. Respectively analyze the characteristics of the power supply side and demand side in different season, point out the main problems of dispatching work.Next, on the basis of existing, this article carries on the optimization in strategy level. By defining the objective function and constraint conditions, the mission of scheduling is conversed mathematical optimization problem. Turn the abstract scheduling policies to the specific algorithm, and use the MATLAB programming platform to achieve the calculation of thermoelectric plan scheduling, thus the result can be output quickly. Arrange result is checked by use of various constraint conditions, to prove that the result accord with the actual demand of power grid. Through developing innovative scheduling strategy and adjusting key parameters in the process of the scheduling, the optimized arrangement result becomes better than that of the actual operating process.Considering the pressure to power grid operation brought by the contradiction between the peak shaving and temperature constraint in summer, this article also studies the feasibility that use the inlet cooling to help improve the output of gas turbine at high temperature, and considers the use of Maisotsenko cycle as cooling method. A thermodynamic calculation model of the gas turbine is established, and effect of the change of inlet temperature on the output capacity of gas turbine is analyzed through the model. Based on the theory of Maisotsenko cycle, dew point indirect evaporative cooler is designed. On this basis, performance of dew point indirect evaporative cooler is analyzed from three aspects consisting of temperature drop, pressure drop, and power consumption, which includes the effect of ambient temperature and relative humidity on the temperature drop, the effect of refrigerant flow on pressure loss, and the effect of cooling capacity on the power consumption. By use of the model, output power and efficiency are taken as indexes to numerical simulate the changing situation of the gas turbine’s performance under environmental change. Three inlet cooling ways are compared, including no inlet cooling, direct spraying cooling, and indirect cooling based on Maisotsenko cycle.
