Nuclear Reactor Pump Arrangement Backflow Prevention
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Solution Overview
Problem
Pump arrangements in nuclear reactors experience undesirable volumetric losses due to reverse rotation and increased flow resistance, which are not effectively mitigated by existing complex and expensive backstops.
Innovation Solution
A pump arrangement featuring a diffuser and a valve device with a valve body that interacts as a seat, eliminating the need for a complex backstop by preventing backflow and utilizing pressure equalization through axial bores and recesses to maintain the valve open during operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a complex non-return valve in the form of flaps closing off a flow channel is used, then reverse rotation can be prevented, but the device complexity and manufacturing cost increase significantly
Solution Approach 1:
The invention extracts the essential function of preventing backflow (stopping reverse rotation) from the complex flap-based non-return valve mechanism. By removing the elaborate flap structure and retaining only the critical pressure-containing elements (diffuser and valve body), the solution achieves reverse rotation prevention with significantly reduced device complexity.
Solution Approach 2:
The invention replaces the expensive, complex flap-based backstop with a simpler, more economical valve device consisting of a valve body, valve cage, and spring. This simplified mechanism achieves the same functional outcome (preventing reverse rotation) at lower manufacturing cost and structural complexity.
2Loss of energy
If a complex backstop is installed to prevent reverse rotation, then volumetric losses are reduced, but the manufacturing cost and structural complexity increase
Solution Approach 1:
The invention extracts the essential energy-saving function (preventing backflow that causes volumetric losses) from the complex backstop mechanism. By retaining only the necessary pressure-containing components (diffuser opening as valve seat, valve body) and removing unnecessary structural elements, the solution reduces volumetric losses while maintaining manufacturing simplicity.
Solution Approach 2:
The invention replaces the expensive, complex backstop structure with a simpler, more economical valve device that uses readily manufacturable components (valve body, valve cage, spring). This achieves the same energy-saving outcome (reducing volumetric losses) with significantly improved ease of manufacture.
3Reliability
If pump arrangements are operated in parallel for redundancy, then operational reliability is improved, but the risk of reverse rotation and energy loss increases when pumps are switched off or fail
Solution Approach 1:
The invention applies preliminary action by pre-equipping each pump arrangement with a valve device that automatically prevents backflow. This preliminary protective measure ensures that when pumps are switched off or fail in a parallel configuration, they cannot rotate backwards and cause energy losses, thereby enabling reliable parallel operation without the penalty of reverse rotation.
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 solution completely avoids reverse rotation and associated volumetric losses, enhancing operational efficiency and reducing energy loss while simplifying the design and manufacturing process.
Implementation Method 1
a valve spring (37) arranged in the valve cage (36) and a valve body (38) which is displaceably arranged in the valve cage (36) and is subjected to a spring force by the valve spring (37)
Implementation Method 2
at least one axial bore (45) is formed in the ring collar (40) of the valve cage (36), in which at least one tube (46) is inserted, which extends into a recess (47) in the ring (26) of the diffuser (19). With each switching operation of the valve device (35), pressure equalization takes place via the axial bore (45), tube (46) and recess (47)
Data Source
Figure 1
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Figure 3
AI summary
The invention relates to a pump arrangement (2) for arranging on a nuclear reactor and for conveying exchanger liquid which is heated in the reactor, having a motor part (4) and a pump part (3) which has a housing (7), wherein a diffuser (19) and a valve device (35) are arranged in an interior (14) of the housing (7), and an opening (25) of the diffuser (19) is configured as a valve seat for a valve body (38) of the valve device (35).