Multistage Supercharger System for Engine Cylinder Balance
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Solution Overview
Problem
In engines with multiple cylinders, achieving uniform combustion by equalizing the mass and flow velocity of the gas mixture supplied to each cylinder is challenging due to differing exhaust gas temperatures and flow rates, leading to inefficient operation of superchargers.
Innovation Solution
The engine system employs a multistage supercharging configuration with high-pressure and low-pressure stage superchargers, where each high-pressure stage supercharger is driven by an exhaust gas from a corresponding cylinder group, and low-pressure stage superchargers are driven by the exhaust gas from a high-pressure stage supercharger, with gas flow optimized to match the rotational direction of the compressors, ensuring equal air-intake flow rates and pressure ratios between cylinder groups.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a plurality of exhaust turbine type superchargers are used to achieve high output and low fuel consumption, then the engine can operate more efficiently, but the turbine outputs differ when exhaust gas temperature and flow rate differ between cylinder groups, causing the superchargers to operate off their planned operating points and potentially beyond surge lines
Solution Approach 1:
The patent merges the exhaust gas flow paths and supercharger systems between the two cylinder groups. Specifically, it combines the exhaust gases from both cylinder groups into a common exhaust manifold and uses a single supercharger with a common turbine that processes the combined exhaust flow, allowing the supercharger to operate at a stable, optimized operating point regardless of individual cylinder group variations
Solution Approach 2:
The patent segments the supercharging function into two distinct stages: a first-stage supercharger that handles exhaust from one cylinder group and a second-stage supercharger that handles exhaust from the other cylinder group. Each stage operates independently with its own turbine and compressor, allowing each to be optimized for its specific exhaust characteristics while collectively providing balanced air supply to both cylinder groups
2Ease of operation
If exhaust gases from different cylinder groups are directed to separate superchargers, then each supercharger can be driven by its corresponding cylinder group's exhaust, but the differing exhaust energies cause unequal air-intake flow rates and pressure ratios between cylinder groups
Solution Approach 1:
The patent merges the exhaust gas flow paths and supercharger systems between the two cylinder groups. Specifically, it combines the exhaust gases from both cylinder groups into a common exhaust manifold and uses a single supercharger with a common turbine that processes the combined exhaust flow, allowing the supercharger to operate at a stable, optimized operating point regardless of individual cylinder group variations
Solution Approach 2:
The patent segments the supercharging function into two distinct stages: a first-stage supercharger that handles exhaust from one cylinder group and a second-stage supercharger that handles exhaust from the other cylinder group. Each stage operates independently with its own turbine and compressor, allowing each to be optimized for its specific exhaust characteristics while collectively providing balanced air supply to both cylinder groups
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 configuration maintains equal air-supply flow rates and pressure ratios between cylinder groups, even with differing exhaust energies, enhancing operational efficiency and preventing surge or choke conditions in the superchargers.
Implementation Method 1
a high-pressure stage turbine driven by the exhaust gas of the corresponding cylinder group
Implementation Method 2
a high-pressure stage compressor rotated by driving of the high-pressure stage turbine and configured to compress a gas supplied to the corresponding cylinder group
Implementation Method 3
a low-pressure stage turbine driven by an exhaust gas discharged from the high-pressure stage turbine
Implementation Method 4
a low-pressure stage compressor rotated by driving of the low-pressure stage turbine and configured to compress a gas supplied to a high-pressure stage compressor
Data Source
AI summary
A engine system is provided with: a plurality of cylinder groups which burn a gas mixture and discharge an exhaust gas; a plurality of high-pressure stage superchargers each having high-pressure stage turbines driven by the exhaust gas from the corresponding cylinder group and high-pressure stage compressors rotated by driving of the high-pressure stage turbines and configured to compress a gas supplied to the corresponding cylinder group; and a plurality of low-pressure stage superchargers having a low-pressure stage turbine driven by an exhaust gas discharged from the high-pressure stage turbine of the high-pressure supercharger which is any one of the plurality of high-pressure stage superchargers, and a low-pressure stage compressor rotated by driving of the low-pressure stage turbine and configured to compress a gas supplied to the high-pressure stage compressor of the high-pressure stage supercharger other than the one high-pressure stage supercharger.