汽轮机DEH阀门控制的研究

发布时间：2018-06-25 08:56

本文选题：DEH系统 + 阀门　；参考：《华北电力大学(北京)》2016年硕士论文

【摘要】：随着我国电力工业的发展,逐渐增加的电网容量,电网峰谷差的慢慢扩大,电网的构成也在发生变化。许多的大型火电机组都参与电网的调峰。现代发电机组中,汽轮机均采用DEH系统进行控制,以便实现对各进汽阀门的统一管理和控制。为了提高其运行经济性,对汽轮机的阀门管理环节进行研究与改进具有一定的工程应用意义。本文的主要工作如下：首先简述了汽轮机调速系统的构成、工作机理及功能。针对机组进行甩负荷试验、阀门关闭时间试验、阀门严密性试验、超速试验、OPC试验,基于试验所得到大量实际生产数据,深入分析调速系统的实际性能指标以及影响因素。其次建立了DEH系统阀门流量特性的数学模型,对其非线性环节进行详细探讨并进行线性化处理。采用BP神经网络建立汽轮机单个调节汽阀特性方程,完成阀门流量特性曲线优化。在单阀和顺序阀的管理模式下,基于最小二乘法获取阀门流量和阀门开度变化的数据表及曲线。最后针对汽轮机阀门进行了整定试验,试验数据为汽轮机阀门特性整定优化的参考数据,然后利用汽轮机阀门特性方程计算出汽轮机阀门整定优化的理论数据。所得新阀门流量特性曲线较原阀门流量特性曲线更加平缓。完成新阀门特性下的机组应用,对比机组单阀顺序阀启动时,机组振动有明显改善,一次调频性能良好,机组热耗降低,机组阀门的进汽节流损失降低,提高了机组稳定性与经济性。
[Abstract]:With the development of the electric power industry in China, the increasing power network capacity and the difference between peak and valley of the power network are gradually expanding, and the composition of the power network is also changing. Many large thermal power units are involved in the power grid peak-shaving. In modern generating sets, the steam turbine is controlled by DEH system in order to realize the unified management and control of each intake valve. In order to improve its operation economy, the research and improvement of steam turbine valve management have certain engineering application significance. The main work of this paper is as follows: firstly, the composition, working mechanism and function of speed regulating system of steam turbine are briefly introduced. According to load rejection test, valve closing time test, valve tightness test, overspeed test and OPC test, based on a large number of actual production data obtained from the test, the actual performance index and influencing factors of the speed regulating system are deeply analyzed. Secondly, the mathematical model of valve flow characteristics in DEH system is established, and its nonlinear link is discussed in detail and linearized. BP neural network is used to establish the characteristic equation of single regulating valve of steam turbine, and the flow characteristic curve of valve is optimized. In the management mode of single valve and sequential valve, the data table and curve of valve flow and valve opening change are obtained based on least square method. Finally, the setting test of steam turbine valve is carried out. The test data is the reference data for the optimization of steam turbine valve characteristics, and then the theoretical data of steam turbine valve setting optimization is calculated by using the characteristic equation of steam turbine valve. The new valve flow characteristic curve is more gentle than the original valve flow characteristic curve. To complete the unit application under the new valve characteristics, compared with the unit single valve sequence valve start-up, the unit vibration has obvious improvement, the primary frequency modulation performance is good, the unit heat consumption is reduced, the unit valve intake throttle loss is reduced, The stability and economy of the unit are improved.
【学位授予单位】：华北电力大学(北京)
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TM621

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