Refrigeration Controller Switching Between Economy and Precision Modes
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional transport refrigeration systems face challenges in efficiently managing energy consumption and maintaining precise temperature control, especially under varying load conditions and in providing advanced control modes for complex temperature management.
Innovation Solution
A controller is configured to alternate between two refrigeration settings: an energy efficiency mode with lower power consumption and a compensation mode that maintains a tighter temperature range, switching between these modes based on cumulative average temperature thresholds to ensure the temperature remains within a target range around a setpoint.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the refrigerant compressor operates at full capacity to maintain precise temperature control, then temperature control precision is improved, but energy consumption increases
Solution Approach 1:
The system dynamically switches between two operational modes (first mode with tighter temperature control and second mode with relaxed temperature control) based on cumulative average temperature conditions. This dynamic adaptation allows the refrigeration system to optimize between temperature precision and energy consumption by selecting the appropriate mode at different times, rather than operating statically at full capacity continuously.
Solution Approach 2:
The controller periodically evaluates the cumulative average temperature and switches between operational modes accordingly. This periodic assessment and mode switching creates a rhythm of tight control followed by relaxed control, reducing overall energy consumption while maintaining acceptable temperature management through cumulative averaging rather than continuous tight control.
2Measurement precision
If the refrigeration system uses a single mode with tight temperature control, then temperature precision is improved, but energy consumption increases
Solution Approach 1:
The operational space is segmented into two distinct modes: a first mode with tighter temperature control (first threshold margin) and a second mode with relaxed temperature control (second threshold margin). By segmenting the control strategy into discrete modes rather than using a single continuous control approach, the system can selectively apply tight control only when necessary, reducing overall energy consumption while maintaining temperature precision when required.
Solution Approach 2:
The system changes the temperature control parameters (threshold margins) based on cumulative average temperature conditions. When the cumulative average temperature is within acceptable ranges, the system switches to the second mode with larger threshold margins, effectively changing the control parameter to reduce energy consumption. When temperature drift occurs, the system switches to the first mode with tighter control parameters to restore precision.
3Use of energy by moving object
If the refrigeration system alternates between two modes based on cumulative average temperature, then energy consumption is reduced, but system complexity increases
Solution Approach 1:
The controller continuously monitors the cumulative average temperature and uses this feedback to determine when to switch between operational modes. This feedback mechanism automatically adjusts the control strategy based on actual temperature conditions, reducing the need for complex predictive algorithms or manual intervention. The feedback loop simplifies the control logic to a straightforward conditional switch based on measured temperature drift.
Solution Approach 2:
The system performs self-adjustment by automatically switching between modes based on its own temperature measurements and cumulative average calculations. The controller monitors its own performance and autonomously selects the appropriate operational mode without external intervention, reducing the need for complex external control systems or manual operation while achieving energy optimization.
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 approach reduces energy consumption while maintaining precise temperature control, allowing the system to oscillate around a setpoint temperature effectively, ensuring that the cumulative average temperature is within a tightly constrained target range, even under minor deviations.
Implementation Method 1
Air or an air/gas mixture or other gas is drawn from the interior volume of the trailer by means of the evaporator fan(s) associated with the evaporator, passed through the airside of the evaporator in heat exchange relationship with refrigerant whereby the refrigerant absorbs heat from the air, thereby cooling the air.
Data Source
AI summary
A controller for controlling a refrigeration unit, a method, and a refrigeration system are disclosed. In an illustrative embodiment, a controller stores instructions for a first refrigeration setting and a second refrigeration setting, tracks a cumulative average temperature in a refrigeration element, and activates either the first refrigeration setting or the second refrigeration setting. The first refrigeration setting has a lower average power consumption and a higher range of temperature variation than the second refrigeration setting. The controller activates the first refrigeration setting until the cumulative average temperature goes outside a selected temperature range; then the controller activates the second refrigeration setting until the cumulative average temperature is within a target temperature range that has a lower threshold that is greater than the lower threshold of the selected temperature range and an upper threshold that is less than the upper threshold of the selected temperature range.