Method and system for a portable refrigerant recovery unit load controller
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Solution Overview
Problem
Refrigerant recovery units face challenges with startup and operation due to high pressure loads, leading to motor activation issues and energy inefficiency, particularly in portable units with lower torque motor specifications, where conventional solutions like venting refrigerant are undesirable.
Innovation Solution
A load controller system that uses a solenoid valve to open a compressor bypass loop line, synchronized with the motor's start relay, to reduce pressure and current loads during startup and abnormal refrigerant flow, thereby lowering torque requirements and conserving energy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Weight of stationary object
If lower torque motor specifications are used to reduce size, weight, and cost, then portability and affordability are improved, but motor startup and operation reliability deteriorate under high pressure loads
Solution Approach 1:
The bypass valve opens a recirculation path before the motor completes startup, allowing the compressor to build pressure gradually. This preliminary action prevents the motor from facing full compression load immediately, enabling lower torque motors to start reliably without compromising eventual compression capability
Solution Approach 2:
The system dynamically adjusts the compression load by controlling the bypass valve opening based on real-time pressure conditions. When pressure differential across the compressor is high, the bypass valve remains open to reduce load; when pressure equalizes, the bypass closes to enable full compression. This dynamic adaptation allows smaller motors to operate reliably under varying conditions
2Use of energy by moving object
If lower torque motor specifications are used, then energy consumption is reduced, but the unit requires field solutions during startup or refrigerant flow restrictions
Solution Approach 1:
The control system automatically monitors pressure differential across the compressor and self-adjusts the bypass valve accordingly. When the motor experiences high load conditions or refrigerant flow restrictions, the system automatically opens the bypass to reduce load, eliminating the need for manual field interventions while maintaining energy efficiency with lower torque motors
3Reliability
If higher torque motor specifications are used to ensure reliable startup under high pressure loads, then motor startup reliability is improved, but unit size, weight, and cost increase
Solution Approach 1:
The bypass valve creates a recirculation path that allows the compressor to start under reduced load conditions. By preliminarily establishing this alternative flow path, the system enables smaller motors to overcome startup inertia without needing the excessive torque capacity that would be required if the motor had to compress refrigerant immediately at full capacity
Solution Approach 2:
The bypass valve acts as an intermediary mechanism between the motor and the compression load. It mediates the relationship by allowing refrigerant to recirculate through the bypass line when compression conditions are unfavorable, effectively decoupling the motor's torque requirements from the full compression demand and enabling smaller motor selections
4Reliability
If conventional field solutions are used to overcome startup issues, then motor startup problems are resolved, but refrigerant is vented or energy is wasted
Solution Approach 1:
Instead of venting refrigerant to reduce startup load (a harmful action), the system converts this harmful practice into a beneficial controlled recirculation process. The bypass valve intentionally creates a controlled recirculation path that allows the compressor to build pressure gradually using the same refrigerant that would otherwise be vented, transforming a wasteful field solution into an integrated energy-efficient feature
Solution Approach 2:
The system automatically implements the load reduction strategy through the bypass valve without requiring external field interventions. When startup conditions are unfavorable, the control system self-activates the bypass to reduce motor load, eliminating the need for technicians to manually vent refrigerant or implement other energy-wasting field solutions
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 load controller system enables refrigerant recovery units to operate efficiently with lower torque motor specifications, ensuring reliable startup and reducing energy consumption by managing pressure and current loads, thus avoiding the need for higher torque motors or undesirable field solutions.
Implementation Method 1
activating with the motor's start relay a solenoid valve to open a flow path in a compressor bypass loop line
Implementation Method 2
decreasing a pressure load on the compressor's motor upon energization
Data Source
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AI summary
A system and methods associated therewith for providing a load controller for a refrigerant recovery units are disclosed. The load controller can be controlled to operate when the current drawn by the motor increases due to pressure changes caused by abnormal refrigerant flow or during activation of the motor in order to lower the pressure. In some aspects of the present invention, the load controller can lower the pressure by recirculating some of the pressure load through the opening of a compressor bypass loop line. In some embodiments, the current/pressure load may be monitored during the operation of the refrigerant recovery unit and set to act as an emergency shut off and alert system to the user when the system malfunctions.