Problems of Construction Activity in the Underground Space of Downtown Moscow

The problem of shaping and developing underground space in a highly urbanize area, for example, the downtown Moscow neighborhoods undergoing reconstruction, is discussed. Basic attention is focused on damage done by construction and the operation of transportation entities, including parking lots and garages, as well as multifunctional entities and complexes with different degrees of complexity.     

Developing and applying modern methods of leakage monitoring and state estimation of fuel at the Novovoronezh nuclear power plant

The results of developing and implementing the modernized fuel leakage monitoring methods at the shut-down and running reactor of the Novovoronezh nuclear power plant (NPP) are presented. An automated computerized expert system integrated with an in-core monitoring system (ICMS) and installed at the Novovoronezh NPP unit no. 5 is described. If leaky fuel elements appear in the core, the system allows one to perform on-line assessment of the parameters of leaky fuel assemblies (FAs). The computer expert system units designed for optimizing the operating regimes and enhancing the fuel usage efficiency at the Novovoronezh NPP unit no. 5 are now being developed.     

Experience gained from the development and results from tests of the equipment of the Kalinin NPP Unit 4 regeneration and intermediate steam separation and reheating system

The equipment of the Kalinin NPP Unit 4 regeneration, intermediate separation, and steam reheating (ISSR) systems is described and the results of their static and dynamic tests are presented. It was shown from an analysis of test results that the equipment of the regeneration and ISSR systems produce the design thermal and hydraulic characteristics in static and dynamic modes of its operation. Specialists of the Central boiler-Turbine Institute Research and Production Association have developed procedures and computer programs for calculating the system of direct-contact horizontal low-pressure heaters (connected according to the gravity circuit arrangement jointly with the second-stage electrically-driven condensate pumps) and the ISSR system, the results of which are in satisfactory agreement with experimental data. The drawbacks of the layout solutions due to which cavitation failure of the pumps may occur are considered. Technical solutions aimed at securing stable operation of the equipment of regeneration and ISSR systems are proposed. The process arrangement for heating the chamber-type high-pressure heaters adopted at the Kalinin NPP is analyzed. The version of this circuit developed at the Central Boiler-Turbine Institute Research and Production Association that allows the heating rate equal to 1°C/min to be obtained is proposed.     

A control for an insectomorphic robot in motion along a vertical corner and a horizontal beam

The problems of climbing a vertical corner and of moving on a horizontal beam while maintaining dynamic balance are solved for a six-legged robot. The opening angle of the comer is equal to Gp/2, and robot climbs it from a horizontal supporting surface. The motion is implemented using dry friction forces. The motion pattern in the passage from the horizontal surface on the corner and the motion in the upward direction are determined by the structure of the gallop gait. Using computer simulation, it is shown that a friction coefficient equal to 1.1 is sufficient for implementation of the motion constructed. In the motion on a narrow beam, the robot goes by a diagonal gait on the front and back legs. The middle legs are used as fly wheels in order to control the kinetic moment of the body relative to the supporting diagonal to reach robot stability in the top position. A PD-controller is designed that provides the required control of the relative motion of the middle legs. The results of computer simulation of the controlled robot dynamics are presented.     

Investigation of droplet size distribution in two-phase flows using a combined method for recording droplet fluorescence and diffraction scattering of light

A prototype of a combined measurement system (MS) based on the fluorescent and small-angle methods of determining the parameters of a fuel-air spray using a pulsed laser as a light source and a color digital video camera to record spray sections was designed and tested. The tests of the MS showed that it has good performance and is suitable for determining the characteristics of advanced atomizers in a pressure chamber. Spatial concentration distributions of aerosols generated by a centrifugal atomizer were studied. Distributions of time-averaged Sauter diameters of droplets, their concentration, and the circumferential inhomogeneity of droplet concentration in the spray cross section were obtained. A study of fuel atomization from a plate was performed showing the possibility of using this device in power plants to improve the atomization performance compared to the atomization of a free jet in crossflow.