Analysis and selection of high pressure heaters design for a new generation of NPP with BN-1200 reactor plant

Abstract

In the development of advanced high-power steam-turbine plants (STP), special attention is placed on the design of reliable and economical high-pressure heater (HPH) capable to maintain the specified thermal hydraulic performance during the entire service life. Comparative analysis of the known designs of HPH, such as the spiral-collector HPH, the collector-coiled HPH, the collector-platen HPH, modular HPH, and the chamber HPH, was carried out. The advantages and disadvantages of each design were pointed. For better comparison, the heaters are separated into two groups—horizontal and vertical ones. The weight and dimension characteristics, the materials and features of the basic elements, and operating features of variety HPH are presented. At operating the spiral-collector HPH used in the majority of regenerative schemes of high-pressure STP of thermal and nuclear power plants, the disadvantages reducing the economy and reliability of their operation were revealed. The recommendations directed to the reliability growth of HPH, the decrease of subcooling the feed water, the increase of compactness are stated. Some of these were developed by the specialists of OAO NPO TsKTI and are successfully implemented on the thermal power plants and nuclear power plants. Technical solutions to reduce the cost of regeneration system and the weight of chamber HPH, reduce the thickness of the tube plate of HPH, and reliability assurance of the cooler of steam and condensate built in the HPH casing under all operating conditions were proposed. Three types of feed water chambers for vertical and horizontal chamber HPH are considered in detail, the constructive solutions that have been implemented in HPH of the regeneration system of turbines of 1000 and 1200 MW capacity with water-moderated water-cooled power reactor (WMWCPR) are described. The optimal design of HPH for the regeneration system of high-pressure turbine plant with BN-1200 reactor was selected.