Gravity Rundown Tank Layout for Turbomachinery Pump Switchover
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional gravity rundown lubrication tanks in turbomachinery systems provide emergency lubrication only after an emergency shutdown, failing to offer backup lubrication during switchover operations and being prone to failures due to maintenance and wear issues with separate hydraulic accumulators.
Innovation Solution
Modifying gravity rundown lubrication tanks to provide both accumulator action pressure-flow and emergency lubrication by elevating them to create a static pressure greater than the shutdown trip pressure threshold, allowing for backup lubrication during switchover and emergency shutdowns, and potentially using dual tanks to extend the duration of lubrication fluid supply.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a gravity rundown lubrication tank is used for emergency lubrication only, then the system provides backup lubrication during coastdown, but it fails to provide lubrication during switchover operations and requires separate hydraulic accumulators
Solution Approach 1:
The patent combines the emergency lubrication tank and hydraulic accumulator into a single integrated gravity rundown lubrication tank. The tank is elevated to a height that creates static pressure exceeding the shutdown trip pressure threshold, enabling it to perform both emergency lubrication during coastdown and provide pressure backup during switchover operations, thereby eliminating the need for separate accumulator components
Solution Approach 2:
The gravity rundown lubrication tank is designed to perform multiple functions: it provides emergency lubrication during coastdown operations and simultaneously serves as a pressure backup source during pump switchover operations. By elevating the tank to create sufficient static pressure, a single component fulfills roles that previously required separate systems
2Reliability
If separate hydraulic accumulators are used for backup pressure, then switchover lubrication is provided, but maintenance and wear issues arise
Solution Approach 1:
The patent extracts the accumulator function from the system and integrates it into the gravity rundown lubrication tank. By eliminating the separate hydraulic accumulator component and its associated maintenance requirements, the system reduces wear issues and simplifies maintenance while maintaining backup pressure reliability through the elevated tank's static pressure
3Reliability
If the gravity rundown tank is elevated to provide static pressure greater than shutdown trip pressure, then backup lubrication during switchover is enabled, but the tank requires greater elevation height
Solution Approach 1:
The patent changes the pressure parameter threshold by elevating the tank height so that the static pressure exceeds the shutdown trip pressure threshold. This parameter change enables the tank to activate during switchover operations rather than only during coastdown, providing backup lubrication capability while accepting the trade-off of increased elevation height
4Productivity
If standby pumps are given more time to initiate, then unnecessary shutdowns are minimized, but the response time to critical pressure drops may be delayed
Solution Approach 1:
The elevated gravity rundown lubrication tank is pre-positioned to provide immediate static pressure backup when pressure drops occur during switchover operations. This preliminary action allows standby pumps additional time to initiate and reach full operation without causing unnecessary shutdowns, as the elevated tank provides immediate pressure support during the transition period
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 modification eliminates the need for separate accumulators, enhances operational reliability by using gravity as a more reliable motive force, reduces maintenance, and extends the time for standby pumps to initiate, thereby minimizing unnecessary shutdowns and costs.
Implementation Method 1
elevating them to create a static pressure greater than the shutdown trip pressure threshold, allowing for backup lubrication during switchover
Implementation Method 2
by elevating them to create a static pressure greater than the shutdown trip pressure threshold
Implementation Method 3
The gravity rundown lubrication tank provides emergency lubrication to the turbomachinery bearing during coastdown
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A pressurized lubrication system 122 for turbomachinery includes a gravity rundown lubrication tank 116 raised vertically above a turbomachinery train. The gravity rundown tank 116 is typically designed to provide emergency fluid lubrication during shutdown if the main and standby lubrication pumps fail to operate. This invention describes a gravity rundown tank with additional novel function of providing higher pressure accumulator action lubrication fluid to delay and prevent a shutdown trip of the turbomachinery. The gravity rundown tank with novel features can be a single tank with multiple functions, or a plurality of tanks utilizing gravity pressure to ensure emergency lubrication at rundown, and providing accumulator action delay pressure and flow when switching from main to standby lubrication pumps. This improvement in the state of the art leads to eliminating the need for conventional equipment such as accumulators thus providing higher lubrication system reliability and minimizing cost and complexity.