Design of a capacitor

In May 2022, the Leningrad Metal Plant, a branch of OJSC Power Machines, contacted AO SUZMK-Engineering due to the need to design and develop design documentation for the 215KP-9800-1 Condenser for Surgutskaya GRES-1 Station No. 16. Having extensive experience in designing heat exchange equipment for various industries, SUZMK-Engineering specialists accepted the task of designing new equipment for themselves.
The device is a horizontal two-section subturbine vacuum condenser with two water passes in each section. The number of pipes is about 13,000, the length of the pipes is about 9,000 mm, the material is MNZh5-1. During the design, various calculation methods were used, as well as an analysis of the operation of similar equipment. After selecting the fundamental design of the analogue, verification calculations were carried out using various methods and a systematic analysis of the convergence of the results with the actual parameters of the operating equipment. As a result, dependencies were identified that most accurately reflected the thermal-hydraulic characteristics of the device, after which the design of the device required in accordance with the technical specifications was selected and approved.

In addition to the "LMZ" method, satisfactory results in all modes were also shown by calculations performed according to the methods of RD 34.30.104-82 "Guidelines for thermal calculation of surface condensers of powerful turbines of thermal and nuclear power plants" and, also, proposed by the Institute of Heat Exchange Equipment of the USA.

Subsequently, the accepted and approved design of the Condenser was subjected to a detailed strength calculation, first by selecting the main dimensions and thicknesses, and then a strength check in accordance with GOST 34233.1-34233.12, GOST 34283. The design was checked by verification calculation using the finite element method with the determination of the stress-strain state in the main power elements of the Condenser using the "ANSYS" program.

The calculation showed that the device provides::

• static strength during normal operation for a service life of 40 years;
• static strength during hydraulic tests;
• vibration strength;
• stability;
• cyclic strength.

A calculation was also performed for seismic impacts of 8 points on the MSK-64 scale. The calculation showed that the strength of the Capacitor is ensured in accordance with the requirements of GOST 34283-2017. "Vessels and apparatuses. Standards and methods for calculating strength under wind, seismic and other external loads" and NP-031-01. "Standards for the design of earthquake-resistant nuclear power plants". Verification calculation and determination of the stress-strain state of the Capacitor were also carried out according to the program. A full-scale three-dimensional finite element model was built to assess the strength of the Capacitor from the impact of seismic design loads.

The design documentation was developed in the import-independent automated three-dimensional design system KOMPAS-3D using layout geometry and parameterization of some typical parts. The detailed three-dimensional model of the product contains 178 subassemblies, 17189 parts and 4476 library components. The designers worked on the creation of the working design documentation of the Capacitor from receiving the technical specifications and final initial data to issuing the documentation for production for 4 months, not counting the changes and adjustments made by the Customer during the design process. The documentation was prepared in strict accordance with the Unified System for Design Documentation and the Customer's requirements.

During the design process, the following complexities were also considered and taken into account:

• use of vibration dampers to protect the device from seismic loads;
• special screw supports for conducting hydrotests of the condenser;
• сalculation of the strength of the Condenser and coordination of loads on the condenser nozzles from the connected pipelines;
• сalculation of the movements of the Condenser nozzles depending on the coordinates of the fixed point;
• design of the steam discharge collector from the high-speed pressure-reducing and cooling unit (HRRU);
• strengthening the walls of the apparatus with stiffeners and ties;
• design of steam receiving devices;
• adjustment of the design and correction of overall dimensions for the location of building structures and installation dimensions in the turbine room.
• other nuances and subtleties of the design, introduced based on the experience of operating similar structures, such as reinforcement of welded seams, the use of equalizing vessels, compensators, etc.

Despite all the difficulties that arose during the design of the Capacitor, the work was completed efficiently and on time. The result of the work satisfied the customer. Our specialists gained invaluable experience in designing complex equipment of this level.
The Capacitor is currently being manufactured. Specialists of JSC "SUZMK-Engineering" provide author's supervision of the project and, if necessary, make the necessary adjustments and clarifications.
The task has been successfully completed!