Multiple-Stage Compressor Bypass Pipe Downstream Motor Routing
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Solution Overview
Problem
The existing multiple-stage compressor with a bypass pipe connected to the refrigerant passage upstream of the electric motor experiences overheating and pressure losses due to refrigerant passing through the motor, leading to decreased efficiency, especially when operating at low pressure ratios.
Innovation Solution
The bypass pipe is connected to the refrigerant passage downstream of the electric motor, allowing the refrigerant to bypass the motor and reducing overheating and pressure losses, with optional branching from the suction pipe upstream of an accumulator and joining with an injection pipe to minimize pipe connections and vibrations, and a valve for selective operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the bypass pipe is connected to the refrigerant passage upstream of the electric motor, then the bypass function can be achieved, but the refrigerant passes through the motor causing overheating and pressure losses
Solution Approach 1:
The patent extracts the harmful effect by routing the bypass pipe to connect the suction pipe directly to the high-stage side compression mechanism, excluding the electric motor from the bypass path. This extraction removes the source of overheating and pressure losses while preserving the bypass capability for capacity control.
2Device complexity
If the bypass pipe is connected upstream of the electric motor, then the bypass structure is simpler, but the refrigerant flow causes efficiency degradation
Solution Approach 1:
The patent introduces an intermediary connection point at the high-stage side compression mechanism as the mediator between the suction pipe and the discharge. This intermediary routing allows the bypass function to be achieved without the refrigerant passing through the electric motor, thereby maintaining compression efficiency while preserving bypass capability.
3Length of moving object
If the bypass pipe allows refrigerant to pass through the electric motor, then the bypass path is shorter, but overheat loss occurs
Solution Approach 1:
The patent extracts the electric motor from the bypass refrigerant path, creating a separate routing that connects the suction pipe directly to the high-stage side compression mechanism. This extraction eliminates the thermal interaction between the refrigerant and motor, preventing overheat loss while achieving the bypass function.
4Ease of manufacture
If the bypass pipe is connected upstream of the electric motor, then the connection is easier, but pressure loss occurs due to narrow gaps
Solution Approach 1:
The patent uses the high-stage side compression mechanism as an intermediary connection point that provides a direct, open pathway for the bypass refrigerant flow. This intermediary routing avoids the narrow gaps between the motor and housing, eliminating pressure losses while maintaining ease of manufacture through straightforward pipe connections.
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 enhances the efficiency of the multiple-stage compressor by preventing overheating and pressure losses, improving operation at low pressure ratios and reducing the risk of pipe breakage, while also reducing costs and complexity.
Implementation Method 1
The electric motor generates heat by being operated. Therefore, in the refrigerant passing through the electric motor, an overheat loss occurs.
Implementation Method 2
the refrigerant arrives at the high-stage side compression mechanism after passing through a gap in the electric motor or a gap between the electric motor and the housing, and this gap is narrow. Therefore, in the refrigerant passing through the electric motor, a pressure loss occurs.
Data Source
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AI summary
There is provided a highly efficient multiple-stage compressor provided with a bypass pipe. A multiple-stage compressor 11 comprises a sealed housing 12; a low-stage side compression mechanism 13 and a high-stage side compression mechanism 15, both being provided in the sealed housing 12; an electric motor 14 for driving the low-stage side compression mechanism 13 and the high-stage side compression mechanism 15; a suction pipe 21 for supplying a refrigerant to the low-stage side compression mechanism 13; a discharge pipe 19 connected to the sealed housing 12 to discharge the refrigerant compressed by the high-stage side compression mechanism 15; a bypass pipe 22 branched from the suction pipe 21 to allow a cavity 12a on the refrigerant passage downstream side of the electric motor 14 and the suction pipe 21 to communicate with each other; and a valve 23 provided in the bypass pipe 22 to selectively permit or inhibit the supply of refrigerant to an intermediate-pressure chamber. Figure 2