Transport Refrigeration Load Control During Heat Exchanger Mode Changes
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Solution Overview
Problem
Transport refrigeration systems (TRS) face challenges in managing power source loading during operational mode changes, leading to potential overloading beyond predefined revolutions per minute (RPM) bandwidth and power limits, which can result in inefficiencies and non-compliance with regulations.
Innovation Solution
A method and system that utilize a controller to identify operational mode changes, obtain parameter data, determine and perform load control actions to prevent power source overloading, by adjusting refrigerant flow, fan speed, engine speed, or compressor unloading, ensuring the power source remains within predefined RPM bandwidth and power limits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If operational mode change is performed without load control, then heat exchanger unit can change mode quickly, but power source may exceed predefined RPM bandwidth and power limits
Solution Approach 1:
The controller performs preliminary actions by identifying the operational mode change request and calculating the future load before the mode change occurs. Load control actions are determined in advance and applied during a preparation period to prevent power source overloading, ensuring the system transitions smoothly without exceeding RPM bandwidth or power limits.
2Reliability
If load control actions are applied during operational mode change, then power source remains within RPM bandwidth and power limits, but system response time increases
Solution Approach 1:
The controller implements periodic action by applying load control actions during a specific preparation period before the operational mode change, then removing them after the change. This time-bound approach allows the system to maintain power source compliance while minimizing the duration of controlled operation, thus reducing time loss.
3Reliability
If multiple load control actions are performed simultaneously, then power source loading is effectively managed, but system complexity increases
Solution Approach 1:
The controller manages power source loading by changing operational parameters of existing components, such as refrigerant flow rate, fan speed, and compressor unloading. These parameter adjustments allow effective load management without adding complex hardware, maintaining simplicity while achieving reliable power source control.
Data Source
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AI summary
Methods and systems for controlling a transport refrigeration system are provided. In one instance, the method includes identifying an operational mode change request for a heat exchanger unit of the transport refrigeration system. The method also includes preparing the transport refrigeration system for the operational mode change of the heat exchanger unit, wherein preparing the transport refrigeration system for the operational mode change of the heat exchanger unit includes performing a load control action, the load control action preventing a power source of the transport refrigeration system from at least one of operating outside of a predefined revolutions per minute (RPM) bandwidth and exceeding a predefined power limit of the power source. Also, the method includes changing the operational mode of the heat exchanger unit; and removing the load control action.