Estimation of the efficiency of combining a npp with a hydrogen facility under conditions of safe use of hydrogen in a steam turbine cycle

THE PURPOSE. System efficiency and competitiveness assess of a new scheme for combining a nuclear power plant with a hydrogen complex based on additional heating of feed water and superheating of live steam in front of the high-pressure cylinder of a steam turbine. METHODS. Basic laws of thermodynamics were applied when developing and substantiating a new scheme for combining a nuclear power plants (NPP) with a hydrogen facility; theoretical regularities were applied of heat engineering; basic regularity were applied of fatigue wear of power equipment and assessment of its working resourse; basic regularities were applied for the assessment of operating costs and net present value (NPV). RESULTS. A new scheme is presented of the combination of a nuclear power plant with a hydrogen facility and a description of its operating principle on the example of a two-circuit nuclear power plant with a VVER-1000 reactor and a C-1000-60 / 1500 turbine. The data are presented on an increase in the productivity of steam generators at nuclear power plants with additional heating of feed water in the range of 235-250 ° C from its nominal value of 230 ° C. The temperature was estimated of live steam superheat depending on the temperature of the additional heating of the feed water. The results are presented of the calculation of the generated peak power by the power unit and the efficiency of conversion of the night off-peak power of the NPP into peak power, as well as the efficiency of the power unit of the NPP depending on the temperature of additional heating of the feed water. Main regularities are given for taking into account the fatigue wear of the main equipment of the hydrogen facility, including the rotor of the NPP turbine in the conditions of the stress-cyclic operation. The results are presented of assessing the cost of peak electricity NPP in combination with a hydrogen facility in comparison with a pumped storage power plant (PSPP) both for the current period and for the future until 2035. CONCLUSION. Hydrogen facility efficiency and competitiveness depends significantly on the intensity of the use of the main equipment in the conditions of the intense-cyclic operation. The hydrogen facility will competitiveness noticeably increase in comparison with the PSPP in the future. Efficiency of the NPP power unit and NPV is highest when the feed water is heated to 235 ° C and superheating of live steam in front of the high-pressure cylinder of the C-1000-60/1500 turbine up to 470°C.The hydrogen facility competes with the PSPP with her specific capital investment at the level of 660 USD / kW, provided that the boosting capabilities of the turbine are used with live steam overheating at 300 ° C and additional heating of feed water to 235°C on the current period. The PSPP does not compete with the hydrogen facility both for the current period and in the future with her specific capital investment of $ 1,500 / kW and above.

A discrete control algorithm synthesis for the live-steam-line heating system

An original mathematic model of a main live-steam-line heating system for the 6 MW turbine is reviewed. The present model is composed from a system of ODE with divergences and constant coefficients, along with an object structure is shown, numerical values of parameters are determined. The transfer function method is used for the model analysis, which is necessary for the main problem resolving. It consists of a discrete control algorithm construction to provide an appropriate heat transition process of an aperiodic type with quality performance required. The con- trol algorithm is based on the functional minimization condition, which is used here as the minimum energy speed up the process. The gradient method and etalon-model method are also used to get an optimal system stage. Due to methods applied, a main variable parameter influence on a system performance is analyzed, optimal adjustment value is retrieved, which allows you to provide the required quality for the heating system performance in all operating modes.

IMPROVING THE DESIGN OF THE FILM DEODORIZER

Приведены характеристики содержащихся в масле одорирующих веществ. Проведен анализ конструкции существующих дезодораторов. Рассчитаны параметры, влияющие на процесс дезодорации в тонком слое. Получена зависимость давления насыщенных паров от температуры дезодорации. На основе проведенных расчетов предложены способы интенсификации процесса дезодорации. Предложена усовершенствованная конструкция дезодоратора, позволяющая интенсифицировать процесс дезодорации: сократить время и уменьшить расход острого пара. The characteristics of the odorizing substances contained in the oil are given. An analysis of the design of already existing deodorizers is given. The parameters affecting the deodorization process in a thin layer are calculated. The dependence of the saturated vapor pressure on the deodorization temperature was obtained. On the basis of the calculations performed, methods for intensifying the deodorization process have been proposed. The proposed improved design of the deodorizer, which allows intensify the deodorization process: to reduce the time and reduce the consumption of live steam.

Evaluation of the State for the Material of the Live Steam Superheater Pipe Coils of V Degree

The main aim of the undertaken research was to evaluate the state of the material of V degree live steam superheater pipe coils made of 10CrMo9-10 (10H2M) chromium-molybdenum steel as well as to determine their usability for further operation. The pipe coils came from a steam boiler working at a power plant. The scope of the research included: a literature analysis of the issue, an elaboration of the research plan, cutting and preparing the test samples, microstructural tests with the use of a light microscope, microstructural tests performed by means of a scanning electron microscope and conclusion drawing on the basis of the performed tests and the literature review. The work presents the steels of which the mentioned elements were made as well as analyzes their working conditions. It describes the most often observed causes of pipe coil damage and presents techniques of controlling the proper efficiency and usability of these elements for further operation.

Operating Performance and Wear Investigations of Brush Seals for Steam Turbine Applications

In recent years brush seals have become more and more an established alternative to existing labyrinth seals due to their increased pressure difference capability per stage in combination with a radial adaptive characteristic. In general brush seal and shaft should be in a concentric position. To utilize the special advantages of a brush seal system the radial adaptive capability of the seal’s bristle pack has to be achieved and guaranteed for the entire operation time. Every mechanism leading to a contact between the rotor and the seal will potentially cause an abrasive wear on both sides. In order to reduce this wear and to improve the operating performance of the brush seal, the influencing parameters resulting from the rotor eccentricity, the thermal gradient and the blown down characteristic of the bristle pack itself have to be understood. For this purpose the TU Braunschweig developed a unique steam test rig for brush seal investigations which allows live steam operations of single and multi stage brush seals up to 50 bar and 450 °C. Equipped with a 300 mm motor driven shaft, long time endurance tests under varying, transient operating conditions can be carried out. In addition to the steam test rig a second cold air test facility with an optical access and a force-displacement measurement unit is used. To analyse the operating bristle pack the brush seal packages and their characteristics were tested in detail under pressure gradients up to 8 bar. The paper shows the results of different seal designs with regards to the blow-down characteristics during a live steam endurance test. Based on these results especially the axial design of the brush seal was found to be an important parameter, since it has a significant influence on potential vibration behaviour of the bristle pack under specific load conditions. In contrast, the transient live steam measurements have shown that a limited amount of movement and vibrations enables an improved radial adaptiveness, leading to reduced leakages during transient operations. Finally the paper introduces a new rotor concept for the steam test rig for further investigations of the brush seal - rotor interaction. It enables the utilization of new and especially varying rotor materials for increased steam parameters as well as the detection of the heat introduction into the rotor during the operating time by rotor-integrated temperature probes.