Transportation refrigeration unit with external DC generator power source
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current transportation refrigeration units face challenges in efficiency, environmental impact, reliability, cost, and weight reduction, particularly in the context of powering refrigeration systems used in trucks and trailers for cargo transport.
Innovation Solution
A transportation refrigeration unit (TRU) system that incorporates a generator power converter to provide AC power based on the TRU's requirements, combined with an energy storage device and a power management system that optimizes power flow from grid power, generator power, and energy storage, ensuring efficient and reliable operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If a combustion engine drives the compressor directly, then the refrigeration system can operate reliably, but the system produces harmful emissions and has poor fuel efficiency
Solution Approach 1:
The patent replaces the direct mechanical coupling between combustion engine and compressor with an electrical system. The engine drives a generator that produces electricity, which then powers an electric motor connected to the compressor. This substitution eliminates direct mechanical transmission and allows for better energy efficiency and reduced emissions through optimized electrical power management.
Solution Approach 2:
The patent introduces a generator and power management system as intermediary components between the engine and compressor. The generator converts mechanical energy to electrical energy, and the power management system optimizes power distribution, acting as a mediator that improves overall system efficiency and reduces harmful emissions while maintaining reliable compressor operation.
2Use of energy by moving object
If an engine-driven generator powers the compressor, then fuel efficiency can be improved, but the system complexity increases
Solution Approach 1:
The patent designs the generator and power management system to serve multiple functions: generating electrical power for the compressor, providing auxiliary power for other TRU components, and enabling flexible operation modes (engine-driven, grid-powered, or battery-powered). This multi-functionality justifies the increased complexity by delivering superior fuel efficiency and operational flexibility.
3Power
If the TRU operates with high power consumption, then cooling capacity is maintained, but energy efficiency deteriorates
Solution Approach 1:
The patent implements dynamic power management that adjusts the operating parameters of the compressor and other TRU components based on real-time cooling demands and available power sources. The system can dynamically switch between different power sources (engine, grid, battery) and adjust compressor speed to match actual cooling needs, maintaining adequate cooling capacity while optimizing energy efficiency.
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 system enhances efficiency, reduces environmental impact, and lowers costs by optimizing power usage and reducing the need for fuel, while also minimizing noise and emissions, with the added benefit of convenient energy storage recharge.
Implementation Method 1
an external DC generator system including a DC generator
Implementation Method 2
a converter operably connected between the generator and the TRU, the converter configured to convert the DC power to a selected AC power
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A transportation refrigeration unit TRU and power system. The TRU (26) and power system including a compressor (58), an evaporator heat exchanger (76) operatively coupled to the compressor (58), and an evaporator fan (98) configured to provide return airflow over the evaporator heat exchanger (76). The system also includes a return air temperature RAT sensor (142) disposed in the return airflow (134) and configured measure the temperature of the return airflow (134), a TRU controller (82) operably connected to the RAT sensor (142) and configured to execute a process to determine an AC power requirement for the TRU (26) based on at least the RAT (142); a generator power converter (164), configured to receive a first DC power (163a) from a generator and transmit a second three phase AC power (165) to a power management system (124), the power management system (124) configured to direct AC power the TRU (26) based on the AC power requirement.