Passive Condenser Cylindrical Collecting Tubes
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Solution Overview
Problem
Conventional passive condensers in nuclear power plants require complex and costly processing due to thick tube sheets and spherical heads, necessitating multiple welds and making 100% radiographic inspection impossible, which compromises containment integrity and safety.
Innovation Solution
The design eliminates the need for tube sheets and spherical heads by using cylindrical collecting tubes with fewer circumferential welds, allowing for 100% radiographic inspection and simpler processing, with flanges welded in a saddle manner and heat exchange tubes connected via butt welding, reducing manufacturing costs and enhancing safety.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If tube sheets and spherical heads are used in conventional passive condensers, then structural strength is improved, but manufacturing complexity and cost increase significantly
Solution Approach 1:
The patent merges the functions of tube sheets and spherical heads into a single integrated shell structure. The heat exchange tubes are directly welded to the shell at specific positions, eliminating the need for separate tube sheets and spherical head components. This integration reduces the number of parts, simplifies manufacturing processes, and lowers costs while maintaining structural integrity through the shell's own strength and the welded connections.
2Reliability
If multiple circumferential welds are required for tube sheets and spherical heads, then structural integrity is improved, but radiographic inspection becomes impossible
Solution Approach 1:
By integrating the tube sheet and spherical head functions into the shell itself, the patent reduces multiple circumferential welds to a single continuous weld seam where heat exchange tubes connect to the shell. This single weld structure is fully accessible for radiographic inspection from both ends of the shell, enabling 100% inspection coverage while maintaining structural integrity through the welded connections.
3Strength
If thick tube sheets and spherical heads are used, then strength requirements are met, but containment openings must be larger
Solution Approach 1:
The integration of tube sheet and spherical head functions into the shell allows for optimized wall thickness distribution. The shell can be designed with uniform or varied thickness to meet strength requirements at critical locations without requiring uniformly thick components throughout. This enables smaller containment openings while maintaining necessary structural strength through targeted reinforcement and optimized welding arrangements.
4Reliability
If conventional head and tube sheet forging processes are used, then manufacturing reliability is improved, but processing cost and time increase
Solution Approach 1:
By eliminating separate forged tube sheets and spherical heads, the patent reduces manufacturing to shell fabrication and tube welding operations. The shell can be manufactured using standard plate fabrication and welding processes, which are more cost-effective and faster than complex multi-component forging and assembly. This simplification maintains reliability through proven welding technologies and reduces both processing cost and manufacturing time.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This design minimizes containment openings, ensures maximum integrity, and improves safety by allowing complete radiographic inspection of welds, reducing manufacturing costs and simplifying processing while maintaining structural integrity and safety performance.
Implementation Method 1
the heat exchange tube bundle including a number of heat exchange tubes... the upper inclined section is fixedly connected to the first flange by butt welding, and the lower inclined section is fixedly connected to the second flange by butt welding
Implementation Method 2
evaporator, condenser, cooling water tank... the condenser plays a key role in the realization of the system's function
Implementation Method 3
the lower collecting tube... defining second through holes for heat exchange tube condensate return ports
Data Source
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AI summary
The present invention provides a passive condenser for a nuclear power plant including: an upper collecting tube defining a number of heat exchange tube steam inlets and having an opening end and a closed end, the opening end being fixedly connected to a first connector; first flanges defining first through holes and being arranged at the positions of the heat exchange tube steam inlets, the first flanges being fixedly connected to the upper collecting tube, with the first through holes being in communication with the heat exchange tube steam inlets; a lower collecting tube defining a number of heat exchange tube condensate return ports and having an opening end and a closed end, and the opening end being fixedly connected to a second connector; second flanges defining second through holes and being arranged at the positions of the heat exchange tube condensate return ports, the second flanges being fixedly connected to the lower collecting tube, with the second through holes being in communication with the heat exchange tube condensate return ports; and a heat exchange tube bundle including a number of heat exchange tubes, each of the heat exchange tubes including an upper inclined section, a middle connecting section and a lower inclined section, the upper inclined section being fixedly connected to the first flange, and the lower inclined section being fixedly connected to the second flange.