Pneumatic Compressor Recirculation Valve for Turbocharger Surge Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Turbocharger surge occurs in natural gas powered engines during transient throttle closing, leading to unstable operation, engine vibration, and varying torque output, as existing technologies fail to effectively control turbocharger operation during this period.
Innovation Solution
An engine system with a compressor recirculation valve (CRV) and gate valve that operate based on pressure changes within the system, utilizing an aspirator, vacuum reservoir, and bleed line to automatically minimize surge without external control, allowing the CRV to reset itself by switching between open positions in response to pressure changes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a throttle is closed quickly in a natural gas powered engine, then air flow control is improved, but turbocharger surge occurs causing unstable operation
Solution Approach 1:
The recirculation valve opens in advance during throttle closing to recirculate compressor outlet air back to the inlet, preventing surge before it occurs. This preliminary action maintains stable turbocharger operation during transient throttle closing by proactively managing air flow rather than reacting after surge begins
Solution Approach 2:
The system uses pressure differential feedback across the recirculation valve to automatically control its opening and closing. The valve responds to pressure changes in the compressor outlet and intake manifolds, creating a self-regulating mechanism that maintains stable operation during throttle transients without external control
2Reliability
If a recirculation valve system is added to control surge, then turbocharger stability is improved, but device complexity increases
Solution Approach 1:
The recirculation valve system is designed to be self-regulating through pressure differential feedback. The valve automatically opens and closes based on pressure changes in the compressor outlet and intake manifolds, eliminating the need for external control systems, sensors, or actuators. This self-service approach maintains stability while minimizing added complexity
Solution Approach 2:
The system uses pneumatic pressure differentials to control the recirculation valve mechanism. Pressure changes in the compressor outlet and intake manifolds directly act on the valve to control its opening and closing, utilizing the existing pneumatic environment rather than adding separate control systems
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 system effectively minimizes surge during boost conditions by automatically adjusting the CRV and gate valve based on pressure changes, eliminating the need for external control and stabilizing engine operation, reducing vibrations and torque variations.
Implementation Method 1
the aspirator evacuates the vacuum reservoir and the gate valve moves to a first open position placing the pneumatic control chamber of the compressor recirculation bypass valve in fluid communication with the downstream air from the compressor thereby closing the compressor recirculation valve. Then when the throttle closes, the gate valve switches from the first open position to a second open position placing the pneumatic control chamber of the compressor recirculation bypass valve in fluid communication with the vacuum reservoir thereby opening the compressor recirculation valve in response to a vacuum reservoir pressure. In the second open position the vacuum reservoir is in fluid communication with the bleed line and fluid is drawn through the bleed valve thereby dissipating the vacuum reservoir pressure
Data Source
AI summary
An engine system having a compressor coupled to an engine and supplying air to an intake manifold, a throttle controlling the supply of air from the compressor to the intake manifold, a vacuum reservoir, an aspirator having its motive section in fluid communication with the air intake system upstream of the compressor and its discharge section in fluid communication downstream of the compressor and a suction port in fluid communication with the vacuum reservoir, a compressor recirculation valve having a pneumatic control chamber in fluid communication with downstream air from the compressor and in fluid communication with the vacuum reservoir, a gate valve controlling the fluid communication of the pneumatic control chamber of the compressor recirculation valve with the downstream air and the vacuum reservoir, and a bleed line having a bleed valve in fluid communication with the vacuum reservoir and the pneumatic control chamber of the compressor recirculation valve.