非线性规划迭代线性化方法在圩垸除涝规划中的应用

本文根据洞庭湖圩垸除涝排水系统非线性规划数学模型的特点,借助离散微分动态规划(DDDP)的思想,利用线性规划(LP)的修正单纯形解法,提出了一种既简单有效,又比较节省计算机时的新的求解非线性规划问题的直接解法——“迭代线性化方法”。实例验证该法是可行的。     

电液比例多功能控制泵的开发研究

变量泵的多功能控制是一种泵的新的控制方式。本文介绍了作者研究开发的电液比例多功能控制泵及其调节原理。文中给出了两种不同的实现方案,并对它们的结构特点进行了分析研究。所开发的多功能泵具有恒压力、恒流量、恒功率及压力流量复合控制等调节功能,有着广泛的工业实用性。试验研究结果表明,该泵各种调节功能的稳态和动态特性均令人满意。     

给水泵站水泵调速的节能分析

分析了给水泵站中水泵调速的节能原理，并以闸阀调节做为对比方案，提出了水泵调速节能的计算方法。     

Heat pump cycles based on the AF–F transition in Fe–Rh alloys induced by tensile stress

The heat-pumping scheme based on the 1st order antiferromagnetism–ferromagnetism transition induced in FeRh alloy by one-dimensional tensile stress is proposed. Using the model S–T diagram for this alloy, the heat-pump cycles are drawn up based both on the transition latent heat absorption and emission when the transition is induced isothermally and on the change in alloy's temperature when the transition is induced adiabatically by applying tensile stress. The calculated values of heat coefficient φ for the cycles are 30 at ΔT=5 К and 20 at ΔT=10 К, where ΔT is the difference between the temperature surrounding and that of the heat receiver. These values are achieved using the tensile stress of 1·10⁹ Pa. The high values of φ make it possible to consider Fe–Rh alloys near the equiatomic composition as an effective refrigerant for elastocaloric heat-pumping near the room temperature.     

MELCOR/MACCS simulation of the TMI-2 severe accident and initial recovery phases, off-site fission product release and consequences

MELCOR has become the preferred code of the Swiss nuclear industry and of PSI for severe accident analysis, on account of its integrated systems-level approach and validation against experiments and more detailed codes, while MACCS is commonly used by safety authorities for independent assessment of off-site consequences, in particular health effects. The present work arises out of a programme to assess MELCOR independently using empirical data consistent with the recommendations of the OECD/CSNI validation matrix for core degradation codes. The MELCOR 1.8.5RD calculations are based on a model for phases 1 and 2 provided by the code developers but with a simplified thermal hydraulic noding in certain regions and the inclusion of a simple representation of the fission product release and transport pathways. The model has also been extended to simulate phases 3, 4, and the continuing initial period of core recovery and stabilisation. These calculations are a first attempt to demonstrate a MELCOR–MACCS capability to simulate the whole plant accident sequence beyond phase 4, including the containment response and off-site consequences arising from fission product release from the containment. Emphasis is placed on the overall accident evolution and whole plant response, rather than the detailed behaviour. Results are compared with observed and deduced data for the major accident signatures and rough estimates for exposure based on off-site monitoring. The results provide a good basis for the NPP analysis foreseen.     

直流开关电源的研究

本文以Dickson电荷泵的基本原理为出发点，研冤了一种输出是负电压的开关电容电源电路参考功率MOSFET的电容模型通过增大驱动电路的电流减小了开关管的上升延时．提高了开关动作的速度，使转换效率得到明显提高。同时，针对开关电容的充放电特点，采用非交叠(nonoverlap-ping)时钟控制信号避免了由于时钟交叠而造成的两级开关同时导通的现象，提高了电路的稳定性和可测试性采用压控震荡器频率的变化来控制功率开关管的开关时间，有效地控制了由于负载变化而造成的输出电压不稳定等现象。此电路结构简单，性能优良，易于集成，可广泛应用于输出负电压的电源产品中。     

大型直接空冷机组真空泵的选择

在缺水的西、北部地区将陆续投运一批大型300、600MW直接空冷凝汽器，针对空冷器后的水环式真空泵是否能完全适应空冷机组运行要求的问题，从真空系统运行中漏气量的确定、容量选择和启动要求、对不同运行工况的适应性、空气漏入率与真空容积的关系等方面论述了大型直接干冷机组真空泵抽吸容量的选择和各种运行因素对容量的影响，提出了适合空冷器在运行中的空气泄漏率的意见：(1)直接空冷机组真空泵容量选择可以参照湿冷机组HEI的标准选取，但应注意采用湿冷机组凝汽器的最低运行压力；(2)空冷器设计应注意其逆流段出口的过冷却符合HEI标准的要求；(3)真空泵运行水温过高使真空泵排出的混合气体中的蒸汽分量加大，其数量可以通过计算求取；(4)对600MW直接空冷机组的空气泄漏率应以不大于30Pa／min为宜。     

软起动器在消防泵控制中的应用

采用软起动器控制消防泵过程中，对电网无过大冲击，可降低系统的配电容量，可消除水泵启、停时水锤效应对设备的损坏，提高了系统设备使用寿命和工作可靠性。介绍了软起动器的工作原理和应用效果。     

高精度智能恒压泵控制系统的设计

高精度智能恒压泵控制系统是以AT89C51单片机为核心,辅以一定的外围器件组成的压力闭环控制系统。该系统通过对压力进行连续采样,由PID调节器运算得出控制参数,对系统执行机构进行控制,从而维持压力恒定。该设计采用了可视化操作系统,使设备操作简单方便。实地测试表明,系统功能与精度完全满足使用要求。     

8BA-18A型水泵填料密封的机械密封改造

通过对佳木斯第二发电厂2#、3#、4#氢冷水泵填料密封改机械密封．解决水泵轴封漏泄，保证水泵的安全稳定运行。