433 / 2018-12-26 16:19:28

Research on Improving Load Response Capability of High Power Unit Considering Low Pressure Heater Bypass ; 低加旁路提升大功率机组负荷响应能力的研究

low pressure heater bypass; load response; the flexibility of the unit 低加旁路；负荷响应；机组灵活性

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As more and more renewable energy is connected to the grid, its randomness and volatility bring greater challenges to the stable operation of the power system. In order to better reduce the impact of new energy power on the power grid, it is urgent to flexibly transform coal-fired units and improve the load response capacity of the units. In this paper, the low pressure heater is taken as the research object, and the potential for rapid and variable load operation of the unit is deeply tapped.
As for the problem of insufficient load response capacity to traditional low pressure heater bypass. An improved low pressure heater bypass structure is proposed, which uses the low temperature economizer to reduce the limitation of deaerator and booster pump to low pressure heater bypass load response capacity. Through setting up the static model of the regenerative system of 1000MW unit, the load response capacity and thermal economy of the unit are simulated under different bypass modes, load sections and operation modes. The results show that the improved low pressure heater bypass system has a strong load response capacity, the No. 6 low pressure heater small bypass system has poor load response capacity and is not suitable for use alone. The short-term power increment of the unit changes linearly with the increase of bypass flow. At the same time, the load response capacity and economy decrease with the decrease of load, but the difference is small under different operation modes. Therefore, the research can provide a certain reference for improving the flexibility of the unit.
随着越来越多的可再生能源接入电网，其随机性和波动性给电力系统的稳定运行带来了更大的挑战。为了更好平抑新能源电力对电网的冲击，急需对燃煤机组进行灵活性改造，提高机组的负荷响应能力。本文以低压加热器为研究对象，深挖机组快速变负荷运行潜力。
针对传统低加旁路负荷响应能力不足的问题，提出一种改进型低加旁路结构，利用低温省煤器降低除氧器和前置泵对低加旁路负荷响应能力的限制。通过搭建1000MW机组回热系统静态模型，在不同旁路方式、负荷段、运行方式下，对机组负荷响应能力、热经济性进行仿真计算。结果表明，改进的低加旁路系统具有较强的负荷响应能力，6号低加小旁路负荷响应能力差，不宜单独使用，机组短时功率增量随旁路流量增大呈线性变化，同时负荷响应能力和经济性随负荷的降低而降低，但在不同运行方式下差异较小。研究可为提高机组灵活性提供一定参考。