EFFICIENCY INVESTIGATION OF THE WAYS OF COMBINING NPP WITH A HYDROGEN COMPLEX FOR THE PURPOSE OF SALE OF HYDROGEN AND GENERATION OF ADDITIONAL ELECTRIC POWER

With an increase in the share of NPPs in the energy system, it becomes necessary for them to participate in the regulation of the electric load schedule. At the same time, the operation of the NPP with the maximum utilization factor of the installed capacity of the reactor was economically and technically justified. One of the promising ways to solve this problem is to install consumers-regulators at NPPs. The hydrogen energy complex can be effectively used as a consumer-regulator. The authors have previously developed an autonomous hydrogen energy generating complex, scientifically substantiated its economic efficiency. As the study has shown, the economic efficiency of an autonomous hydrogen energy complex directly depends on the sale tariffs for electricity. The low cost of electricity sold leads to a deterioration in economic indicators, up to a lack of recoupment. In this regard, as an alternative option, this work considers the possibility of selling hydrogen and oxygen as a commercial product at existing prices. A comparative study for a range of electricity tariffs and prices for hydrogen and oxygen was carried out on the basis of the methodology presented earlier by the authors, which makes it possible to study ways to improve NPPs on the basis of a comprehensive analysis of economic efficiency, safety and system effects achieved during the installation of new and modernization of existed equipment. The results obtained make it possible to choose the type of hydrogen energy complex depending on the operating conditions for the selected region of operation.

IMPLEMENTATION OF THE LEMAITER DAMAGE MODEL IN ANSYS FINITE ELEMENT COMPLEX

In this work, the simplified Lemaitre damage model was integrated into the ANSYS finite element calculation software. The model is implemented as a dynamically linked library of custom material for 2D problems. The model was tested on a cylindrical specimen with an annular cut. The stages of damage accumulation in the numerical experiment coincide with similar numerical experiments known in the literature.

OVERVIEW OF ELECTROMECHANICAL AND OTHER METHODS OF ENERGY CONVERSION FOR EFFICIENT USE OF RESOURCES

This article examines current trends in energy storage systems and their impact on social sphere, as well as the prospects for the development of energy storage systems until 2035. The purpose of this work is to analyze the existing energy storage technologies and the problems they solve in the world and in Russia. To do this, the authors of the article analyzed a database of 467 energy storage projects from the Sandia National Laboratory (DOE Global Energy Storage Database). Conducted research allowed us to assess the technology readiness level for main energy storage types. The political, socio-cultural, economic, legal, technological, environmental risks of the development of energy storage systems until 2035 have been determined.

STUDY OF ELECTRIC MOTORS FOR AUTOMATED SOLAR PANEL CLEANING SYSTEMS

One of the main problems faced during solar panels operation is the contamination of their front surfaces. This paper presents the results of solving that problem by means of new equipment design development. The authors have proposed an autonomous and reliable cleaning method with low power consumption and no possibility of panel shading. In connection with the noted criteria, an automated system with a short payback period was created. The article presents a description of the developed device, the results of a study on the choice of an engine, an electric drive. The use of an automated system for cleaning solar panels will allow minimizing the share of human participation in the solar panels cleaning.

CRACK PROPAGATION UNDER INITIAL MODE II CONDITIONS

Series of tests for compact tension shear specimens under mode II and following mixed mode was carried out. Compact tension shear specimens made of steels 34X and P2M, Ti-6Al-4V titanium and 7050 aluminum alloys. During experiments the behavior of the inclined crack angles, kinked crack angles and crack propagation angles, as a function of dimensionless crack length for the curvilinear paths was obtained. The influence of elastic-plastic material properties on the form the curvilinear crack path is established.

Influence of the temperature of the cooling water on the deaeration capacity in the KСS-200-2 condenser

In this paper, the results of the steam turbine condenser tests showing the dependence of the dissolved oxygen concentration and the water cooling temperature are presented. The steam surface condenser with the water cooling system is considered as the first stage of deaeration in the feedwater system of a steam turbine. The aim of this work is trying to investigate and describe the influence of regime factors on the deaeration effect of the steam surface condenser. Regimes with the nominal flow of the steam in the surface condenser were chosen for the estimation. The tests were continuing for 6 months in the range of the temperature of cooling water from 1 to 25 оС. The vacuum system of the steam turbine had a high level of air leakages that decreasing the efficiency of the feedwater dearation. The results show the negative correlation between dissolved oxygen in feedwater and the cooling water temperature. The surge of the concentration of dissolved oxygen was found in the water temperature about 11оС.

Modern opportunities for preparation of ultra-pure water for feeding high-performance boiler plants

The article provides an overview of modern high-performance combined-cycle plants and gas turbine plants with waste heat boilers. The forecast for the introduction of gas turbine equipment at TPPs in the world and in Russia is presented. The classification of gas turbines according to the degree of energy efficiency and operational characteristics is given. Waste heat boilers are characterized in terms of design and associated performance and efficiency. To achieve high operating parameters of gas turbine and boiler equipment, it is necessary to use, among other things, modern water treatment equipment. The article discusses modern effective technologies, the leading place among which is occupied by membrane, and especially baromembrane methods of preparing feed water-waste heat boilers. At the same time, the ion exchange technology remains one of the most demanded at TPPs in the Russian Federation.

Review of models of gradient plasticity theory

Gradient plasticity theories have potential applications for evaluating the load-bearing capacity of structures, since they more accurately describe stress fields in the crack vertex region by including the influence of dislocation distribution density. Gradient plasticity theories take into account scale effects, assuming that stresses depend not only on deformations, but also on the gradient of deformations. The main idea is that the material is strengthened by changing the total density of dislocations, some of which are derived from the stress gradient. These dislocations begin to play a dominant role in the process of metal deformation at the micro level. This paper provides a literature review of gradient plasticity theories that not only rationalize large-scale effects, but also help to understand the processes occurring in the crack vertex region in the presence of the largest plastic deformation gradients.

Numerical investigation of heat transfer and hydrodynamics for in-line drop-shaped tubes bundle

A numerical study using the software package ANSYS has been conducted to investigate fluid flow and heat transfer characteristics for in-line drop-shaped and circular tubes bundles in crossflow. Reynolds number based on equivalent diameter varied in range of 3x103 ≤ Re ≤ 18.7x103. The longitudinal spacing SL= 37, 46.25 mm, while the transversal spacing ST =37 mm. A mathematical and numerical model has been developed for numerical evaluation of heat transfer and hydrodynamic of a studied bundles. The distribution of the pressure coefficient over a half surface of the circular and drop-shaped tubes of the third row was obtained. Correlations of the average Nusselt number and the friction coefficient for the studied bundles in terms of Re were presented. Results showed that pressure coefficient and heat transfer of drop-shaped tubes depend on position of tubes in tubes bundle. The thermal–hydraulic performance of the drop-shaped tubes bundle is about 1,45~ 2,01 и 1,45~ 2,01 times greater than the circular one for SL= 37, 46.25 mm, respectively.

Evaluation of modernization of inclusion of gas exhaust devices of vacuum deaerators

The issue of increasing the reliability of gas exhaust devices remains quite relevant, since a large number of violations of vacuum deaeration of water are associated with their failures. Jet gas removal devices - ejectors, are used as devices for removing non-condensable corrosive gases from vacuum deaerators. The article provides a detailed description of the designs and existing types of steam-jet and water-jet ejectors, provides a classification of ejectors, their scope. Moreover, in this paper, schemes for switching on ejectors are presented, the positive and negative aspects of each of the types of ejectors are considered. In particular, in this work, the scheme of operation of a combined heat and power plant (CHP) with the combined use of steam-jet and water-jet ejectors is considered, and an assessment is made of the modernization carried out at Ulyanovsk CHP-2, associated with an additional installation of a water-jet ejector.