Parallel Hydraulic Accumulator Circuit for Throttling Loss Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Hydraulic drive systems for machines with repeating work cycles face inefficiencies due to varying power demands, leading to significant energy wastage as the fixed displacement pump operates at constant flow, exceeding load requirements, and causing throttling losses.
Innovation Solution
Incorporating a hydraulic accumulator in parallel with the flow control valve, controlled by an electronic controller, to match power generation and consumption, and using an accumulator array with different pressure ranges to closely match load pressures, thereby reducing throttling losses and enhancing energy efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If a fixed displacement pump operates at constant flow, then the pump can meet peak power demands, but significant energy is wasted when the flow exceeds load requirements
Solution Approach 1:
The accumulator is pre-charged to a specific pressure before operation. During low-demand phases, the accumulator stores excess hydraulic energy by accepting fluid from the pump. During high-demand phases, the accumulator discharges stored energy to supplement pump output, eliminating the need for the pump to continuously operate at peak capacity and reducing energy waste during low-demand periods.
Solution Approach 2:
The system dynamically adjusts the accumulator pressure setpoint based on varying load conditions. The electronic controller monitors system parameters and modifies the accumulator charge pressure to optimize energy efficiency across different operating conditions, allowing the system to adapt between meeting peak power demands and minimizing energy waste during partial load operation.
2Reliability
If system pressure is maintained above load pressure with a pressure margin, then the relief valve can control pump outlet pressure, but throttling losses increase due to the pressure drop across the flow control valve
Solution Approach 1:
The electronic controller continuously monitors system pressure and load conditions, then dynamically adjusts the accumulator discharge pressure to match actual load requirements. This feedback mechanism eliminates the need for a fixed pressure margin above load pressure, allowing the system to maintain reliable pressure control while minimizing throttling losses by operating at the minimum necessary pressure differential.
Solution Approach 2:
The system transitions from static pressure control with a fixed relief valve setting to dynamic pressure control where the accumulator discharge pressure varies with load conditions. This dynamic approach allows the system to adapt the pressure margin to actual operational needs, maintaining reliability when required while reducing throttling losses during partial load operation.
3Power
If the pump is sized to meet peak flow demands, then peak power requirements are satisfied, but a significant portion of pump flow is passed to the reservoir without doing useful work
Solution Approach 1:
Instead of discarding excess pump flow to the reservoir during low-demand periods, the system recovers this energy by directing it to charge the accumulator. The accumulator stores this hydraulic energy for later use during peak-demand phases, transforming what would be wasted flow into useful stored energy that contributes to meeting peak power requirements and increasing overall productive output.
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 solution effectively matches hydraulic pressure and flow demands, reducing energy wastage and throttling losses by optimizing the operation of the hydraulic drive circuit, especially in industrial processes with varying load pressures.
Implementation Method 1
Incorporating a hydraulic accumulator in parallel with the flow control valve, controlled by an electronic controller, to match power generation and consumption
Implementation Method 2
The accumulator subsystem includes a charge line valve for selectively opening and closing the charge line, and a discharge line valve for selectively opening and closing the discharge line
Data Source
AI summary
A hydraulic circuit architecture for use in a drive circuit having a hydraulic pump for driving a load is disclosed. The hydraulic circuit architecture includes a flow control valve for controlling a hydraulic fluid flow rate supplied from the hydraulic pump to the load. The hydraulic circuit architecture also includes a hydraulic fluid accumulator arranged in parallel with respect to the flow control valve. Hydraulic circuit architectures having multiple accumulators arranged in parallel with respect to the flow control valve are also disclosed.