Battery-Powered Trailer Reefer With Axle-Driven DC Refrigeration
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Solution Overview
Problem
Existing large-vehicle refrigeration systems, particularly semi-truck reefers, fail to eliminate carbon exhaust emissions and meet idle restriction limits, as they rely on internal combustion engines and AC power systems that are not adaptable to battery power and are inefficient due to multiple power inversions, leading to reliability issues and high maintenance costs.
Innovation Solution
A battery-powered, direct-current (DC) electric motor system that eliminates the need for internal combustion engines, using a combination of high-power generators, heavy-duty axles, and DC power control to provide self-contained, all-electric refrigeration, converting vehicle momentum into electrical power and optimizing power usage to meet emissions standards and operational demands.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If internal combustion engines are used to drive the compressor and other reefer components, then the system can provide sufficient power, but carbon exhaust emissions are generated and idle restriction limits are not met
Solution Approach 1:
The patent replaces the internal combustion engine (mechanical system) with an electric motor system powered by batteries and a generator. The generator converts mechanical energy from the vehicle's motion into electrical energy, which then powers the electric motor driving the compressor, eliminating the need for a separate combustion engine and thus eliminating carbon exhaust emissions while maintaining sufficient refrigeration power.
2Adaptability or versatility
If AC power systems with multiple power inversions are used, then the system can operate with battery power, but critical battery power is wasted and reliability issues arise
Solution Approach 1:
The patent extracts and eliminates the unnecessary power inversion stages from the system. Instead of converting DC battery power to AC and then back to DC, the system uses DC battery power to directly drive the generator, which produces AC power that is then rectified to DC only once to charge the batteries and power the DC electric motor. This streamlined approach removes redundant energy conversions and significantly reduces battery power waste.
3Power
If a separate axle is used to drive the generator, then the generator can be powered independently, but the trailer suspension system is modified and road worthiness is degraded
Solution Approach 1:
The patent makes the existing vehicle axle serve multiple functions: it continues to support the trailer and enable motion while simultaneously driving the generator through a belt or direct connection. This eliminates the need for a separate dedicated axle for generator power, maintaining the original suspension system integrity and road worthiness while providing independent generator power capability.
4Reliability
If constant speed pumps and transmissions are used to match generator rotational speed, then the 60 cycle frequency requirements of AC motor are met, but the system becomes expensive and maintenance heavy
Solution Approach 1:
The patent replaces complex mechanical speed-matching systems (constant speed pumps and transmissions) with an electrical solution. The generator produces variable frequency AC power, which is rectified to DC and then inverted to AC at the required 60 Hz frequency using an electronic inverter. This substitution of mechanical speed control with electronic frequency conversion eliminates the need for complex mechanical components while maintaining reliable frequency stability for the AC motor.
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 solution provides a reliable, economical, and environmentally friendly all-electric semi-trailer reefer system that meets emissions standards, reduces maintenance, and conserves energy by using DC power exclusively, eliminating emissions and the need for separate axles, ensuring road worthiness and efficient refrigeration capacity.
Implementation Method 1
a battery powered direct-current (dc) electric motor instead of an internal combustion engine... using a battery to power one of these ac systems the dc battery power must be continually inverted to single phase ac power... the generator power of an ac system must be inverted to dc power to charge a battery
Implementation Method 2
A battery powered direct-current (dc) electric motor instead of an internal combustion engine... This invention uses a battery powered direct-current (dc) electric motor instead of an internal combustion engine
Data Source
AI summary
Battery powered transport refrigeration assembly for semi-trailers. The assembly relates to large-vehicle refrigeration systems (reefers) and more particularly to semi-truck reefers.