Compressor for heat exchange system, heat exchange system and method for controlling operation of compressor
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Solution Overview
Problem
Dual speed motors in compressors often face torque limitations when switching from low speed to high speed, leading to compressor shutdowns and operational disruptions in heat exchange systems.
Innovation Solution
A compressor system with an upload/download flow path that adjusts suction flow before and after switching between working conditions, using control valves and bypass paths to manage torque and ensure safe operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a dual speed motor is used to enable the compressor to operate under different working conditions, then the integrated part load value (IPLV) is improved, but the torque required during speed switching may exceed the maximum torque the motor can provide, causing the compressor to stop operating
Solution Approach 1:
The upload/download flow path is opened before the dual speed motor switches from low speed to high speed to preliminarily adjust the suction flow. This preliminary action reduces the torque demand during the transition period, preventing the compressor from stopping due to insufficient motor torque, while still enabling the motor to provide two working speeds for improved IPLV
2Speed
If the dual speed motor is switched from low speed to high speed to promote larger suction flow, then the suction flow is increased, but the torque required may exceed the motor's maximum torque capability, causing shutdown
Solution Approach 1:
Before switching from low speed to high speed, the upload/download flow path is opened to preliminarily reduce the suction flow and corresponding torque demand. This allows the motor to successfully complete the speed transition without exceeding its maximum torque capability, after which the suction flow is increased to the required level
Solution Approach 2:
The system dynamically adjusts the suction flow through the upload/download flow path during the speed transition process. The flow path is opened during the transition to reduce torque demand, and closed after transition to restore full suction flow, making the torque requirement adaptable to the motor's capabilities at each stage
Data Source
AI summary
The disclosure relates to compressors for heat exchange systems, heat exchange systems having such compressors, and methods for controlling operation of compressors. The compressor includes a drive device for driving the compressor and having at least a first and second working conditions. An output power of the drive device under the second working condition is greater than an output power under the first working condition. The compressor has at least one upload/download flow path configured to be opened before the drive device is switched from the first working condition to the second working condition to reduce a suction flow of the compressor until current operating parameters of the compressor reach preset values, after which the switching is performed, and to increase the suction flow until the compressor is in a required working state, after the switching is completed.