Development of a throttle and dampening device for the nuclear power plant of icebreaker LK-60

Abstract

In the course of developing designs for mixing heat exchangers that operate on the principle of throttling the working medium on perforated grids, special attention is paid to ensuring the reliability of structures subject to erosive wear when subjected to dripping moisture and temperature stresses.JSC “NPO CKTI” has years of experience in the development of contact-type heat exchangers and was directly involved in the design of separate power plant equipment for LK-60, including a throttle and dampening device (TDD).It provides a description of the functional purpose of the TDD as part of the LK-60 nuclear power plant, the principle of operation and significant differences of the new design from those previously used. It is noted that while in previous designs the TDD included four columns connected in pairs, on LK-60 there are two columns located on top of the condenser. The TDD for LK-60 is designed to receive 132.5 t / h of steam of higher parameters than the previous generation designs intended to receive about 50 t / h of steam.The main technical solutions in the development of the design of the TDD are presented. The design provides access to the throttling lattices for diagnostics and their replacement if necessary which ensures a high degree of maintainability and reliability of the device. Perforation of the lattices arranged in series in the direction of the steam flow is made in such a way that the openings of the previous lattice, if possible, are not located opposite the openings of the subsequent lattice. The distance between the throttling lattices was taken from the conditions for ensuring the design course of the steam throttling process.Results are given of thermal and hydraulic calculations of the TDD. The calculation consists of two main parts. The first part includes thermal and hydraulic calculations with the determination of the degree of perforation of the lattices, the distribution of temperature and vapor pressure over the cross-sections of the TDD, etc. The second part contains the calculation of the cooling condensate injection nozzles.In the course of design studies, strength calculations were performed for all versions of TDD and individual parts. In addition, the nozzles underwent a full test cycle (determination of flow characteristics, water spray quality) in accordance with the test program.