High-Pressure Pump Seal Chamber Pressure Retention Against Leakage
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
High-pressure pumps used for handling supercritical fluids like CO2 and H2S face challenges in preventing leakage of these corrosive and toxic fluids to the exterior, which is critical due to their hazardous nature and environmental impact.
Innovation Solution
A multistage high-pressure pump design incorporating a check valve on the oil supply line, accumulators between the check valve and seal chamber, and a shut-off valve on the oil outlet line, along with a double-casing structure and mechanical seals, ensures that the pressure in the seal chamber is maintained even during emergencies, preventing fluid leakage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a mechanical seal is used in a high-pressure pump handling supercritical fluids, then the pump can operate efficiently, but the risk of fluid leakage to the exterior increases
Solution Approach 1:
A barrier fluid (oil) is introduced as an intermediary substance between the supercritical fluid and the external environment. The barrier fluid is supplied to the seal chamber at a pressure higher than the supercritical fluid pressure, creating a protective barrier that prevents supercritical fluid from leaking outward while allowing the mechanical seal to function. This mediator approach resolves the contradiction by adding a safety layer without compromising pump operation.
Solution Approach 2:
The system proactively prevents fluid leakage by maintaining positive pressure of the barrier fluid in the seal chamber before any leakage can occur. Pressure sensors continuously monitor the barrier fluid pressure, and the control unit activates the oil pump to replenish barrier fluid if pressure drops, thereby preemptively counteracting any potential leakage pathway before it becomes hazardous.
2Ease of operation
If the oil pump stops in an emergency case, then the system responds to the emergency, but the pressure in the seal chamber drops allowing fluid leakage
Solution Approach 1:
Accumulators are pre-filled with pressurized barrier fluid and positioned in the barrier fluid supply line between the oil pump and seal chamber. These accumulators act as emergency reservoirs that automatically discharge barrier fluid to maintain seal chamber pressure when the oil pump fails, ensuring continuous protection without requiring active pump operation during emergencies.
Solution Approach 2:
The accumulators serve as a cushioning backup system that compensates for sudden oil pump failures. By storing pressurized barrier fluid in advance, the system creates a safety buffer that maintains seal integrity during transient pump outages, preventing leakage while allowing the pump to be restarted or replaced without immediate hazard.
3Object-affected harmful factors
If pressure sensors and control systems are added to monitor barrier fluid pressure, then leakage detection capability improves, but the device complexity increases
Solution Approach 1:
Pressure sensors are installed in the barrier fluid supply line to continuously monitor barrier fluid pressure and feed this information back to a control unit. When the sensor detects pressure dropping below a predetermined threshold, the control unit automatically activates the oil pump to replenish barrier fluid, creating a closed-loop feedback system that maintains seal protection without requiring complex manual intervention or monitoring procedures.
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
The design effectively prevents leakage of supercritical fluids, ensuring safety and environmental protection by maintaining pressure within the pump and detecting any leaks through pressure sensors, thus providing a secure and efficient operation.
Implementation Method 1
at least one accumulator located between the check valve and the seal chamber
Implementation Method 2
the pressure of the oil in the seal chamber is maintained
Data Source
Figure 1
Figure 2
AI summary
A multistage high-pressure pump according to the present invention includes a rotational shaft (1), impellers (3) secured to the rotational shaft, a casing (2) configured to house the impellers therein, a mechanical seal (20), a seal chamber (25) that houses the mechanical seal therein, an oil reservoir (30) configured to store oil therein, an oil supply line (26) providing fluid communication between the oil reservoir (30) and the seal chamber (25), an oil pump (31) configured to pressurize the oil from the oil reservoir (30) and supply the oil to the seal chamber (25), a pressure retaining mechanism (32, 34, 35) configured to retain pressure of the oil in the seal chamber (25), and an oil outlet line (27) for discharging the oil from the seal chamber (25). The pressure of the oil in the seal chamber (25) is higher than pressure of the fluid.