小型分布式能源系统的优化设计

发布时间：2018-05-02 09:35

  本文选题：分布式能源 + 燃气-蒸汽联合循环　； 参考：《太原理工大学》2014年硕士论文

【摘要】：分布式能源系统以节能、经济、环保和供能可靠等优势,在我国环境污染严重、能源利用率较低的今天有着广泛的发展前景。目前,国内分布式能源系统主要受并网难、技术不成熟等问题的困扰。 针对国内现有分式能源系统效率低、热电冷负荷调节难等问题,本课题充分利用城市已有天然气一次能源供应管网优势,以提高系统总能利用效率为出发点,基于能量梯级利用的基本原则,设计了一小型燃气-蒸汽联合循环分布式能源系统,为某小区提供1200kW的用电量,并满足其全年用热冷负荷。 该系统充分考虑了各种余热利用,通过建立优化目标函数,分析了节点温差、接近点温差和主蒸汽温度对联合循环发电系统性能的影响,节点温差应取范围内的较大值,使联合循环总功率增加；接近点温差应取范围内的较大值,使联合循环总功率增加；主蒸汽温度增加是提高联合循环效率的最有效措施之一,但主蒸汽温度的增加受限于燃气轮机排气温度。通过计算和分析,给出了该分布式能源系统的燃气轮机、余热锅炉、蒸汽轮机和热泵等装置的选型和优化设计理论。 小型分布式能源系统容量小,余热量小,不足以满足用户所需的热负荷、冷负荷,需另设供热制冷装置。通过设计烟气换热器和直燃型吸收式热泵,优化设计了供热制冷系统,实现了系统的集成优化。最后,计算了该分布式能源系统在供热工况和制冷工况下的系统性能。 所设计的小型分布式能源系统的能源利用效率为92.84%、冬天和夏天CO2减排率分别为70%、57.5%、单位供能成本减小率分别为61.33%、44%。 供热制冷系统共分三部分：小汽轮机抽汽驱动的吸收式热泵一年四季供热水,其供热性能系数COP为1.8；烟气换热器可提供231kW的供暖量；直燃型吸收式热泵供暖制冷系统,冬天供热性能系数COP达2.41,夏天制冷系数ξ为1.25；系统排烟温度可降至50℃。 分布式能源是未来能源技术的重要发展方向,基于燃气-蒸汽联合循环的小型分布式能源系统在中国具有广阔的应用前景。
[Abstract]:With the advantages of energy saving, economy, environmental protection and reliable energy supply, distributed energy system has a broad development prospect in China, where environmental pollution is serious and energy utilization is low. At present, the domestic distributed energy system is mainly troubled by the difficulties of grid connection and immature technology. In view of the problems of low efficiency of existing fractional energy system in China and difficulty in regulating the load of heat and cooling, this paper makes full use of the advantages of primary energy supply network of natural gas in cities, and takes it as the starting point to improve the efficiency of total utilization of the system. Based on the basic principle of energy cascade utilization, a small gas-steam combined cycle distributed energy system is designed, which can provide the power consumption of 1200kW for a residential area and meet its annual heat and cooling load. The system fully considers the utilization of all kinds of residual heat, and analyzes the effect of node temperature difference, proximity point temperature difference and main steam temperature on the performance of combined cycle power generation system by establishing the optimization objective function. The node temperature difference should be taken as a large value in the range. The total power of the combined cycle is increased; the value of the temperature difference at the close point is larger, and the total power of the combined cycle is increased; the increase of the main steam temperature is one of the most effective measures to improve the efficiency of the combined cycle. However, the increase of the main steam temperature is limited by the exhaust temperature of the gas turbine. Through calculation and analysis, the selection and optimization design theory of gas turbine, waste heat boiler, steam turbine and heat pump for the distributed energy system are given. The small distributed energy system has small capacity and small residual heat, so it is not enough to meet the heat load and cooling load required by the user, so it is necessary to set up additional heating and refrigeration equipment. Through the design of flue gas heat exchanger and direct-fired absorption heat pump, the heating and refrigeration system is optimized and the integrated optimization of the system is realized. Finally, the performance of the distributed energy system under heating and refrigeration conditions is calculated. The energy utilization efficiency of the designed small distributed energy system is 92.84, the CO2 emission reduction rate in winter and summer is 70 and 57.5, and the reduction rate of unit energy supply cost is 61.3344. The heating and refrigeration system is divided into three parts: the absorption heat pump driven by small steam turbine provides hot water throughout the year, and its heating performance coefficient (COP) is 1.8; the flue gas heat exchanger can provide the heating quantity of 231kW; the direct-fired absorption heat pump heating and refrigeration system, The heating performance coefficient (COP) is 2.41 in winter and the cooling coefficient 尉 is 1.25 in summer. The exhaust temperature of the system can be reduced to 50 鈩，

本文编号：1833349