Fuel Cell APU Drive for Truck Cabin Air Conditioning
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Solution Overview
Problem
Current methods for providing auxiliary power to line-haul trucks during rest stops or waiting periods are inefficient, as they often require the main engine to remain running, leading to excessive fuel consumption and emissions, and existing solutions like battery-powered or small internal combustion engine systems are either costly, complex, or not practical for widespread adoption.
Innovation Solution
An auxiliary system that includes an air conditioning compressor with a jackshaft and an electric motor connected by a belt, where the electric motor has no clutch, allowing for efficient operation independent of the main engine, and a hydrogen fuel cell system that provides power to the compressor and other loads, ensuring continuous operation without redundant compressors or belt conversions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the main engine is used to power auxiliary loads during rest periods, then the auxiliary systems can operate reliably, but fuel consumption and emissions increase significantly
Solution Approach 1:
The patent segments the power system into two independent parts: the main traction engine for propulsion and a separate auxiliary power unit (APU) for comfort loads. This allows the main engine to be shut down during rest periods while the APU independently powers air conditioning and other auxiliary systems, eliminating unnecessary fuel consumption and emissions.
Solution Approach 2:
The APU acts as an intermediary power source between the main engine and auxiliary loads. Instead of directly coupling auxiliary systems to the main engine, the APU mediates by providing dedicated power for comfort loads, allowing the main engine to operate only when needed for traction.
2Loss of energy
If a battery-powered auxiliary power system is used, then the main engine can be shut down during rest periods, but the battery may run down and require external jump starting
Solution Approach 1:
The system dynamically switches between battery power for starting the APU and APU-generated power for sustained operation. The battery provides initial energy to start the APU, then the APU takes over to power auxiliary loads and recharge the battery, creating a dynamic power management system that prevents battery depletion.
Solution Approach 2:
The system recovers energy by using the APU to recharge the battery during operation. Instead of allowing the battery to deplete, the APU continuously recharges it, transforming the battery from a consumable energy source into a reusable energy storage device that maintains system reliability.
3Reliability
If an independent auxiliary heating ventilating and air conditioning system is provided, then auxiliary loads can be powered during main engine shutdown, but additional weight and complexity are added
Solution Approach 1:
The APU serves multiple functions: it powers the air conditioning compressor, provides electrical power through the generator, and can recharge the battery. This multi-functional design eliminates the need for separate independent HVAC systems, reducing overall system complexity and weight while maintaining reliability.
Solution Approach 2:
The patent merges the power generation function with the air conditioning drive function. The APU both generates electrical power and mechanically drives the AC compressor through a shared drivetrain, combining what would traditionally be separate systems into a unified, more efficient architecture.
4Object-generated harmful factors
If a small internal combustion engine is used for auxiliary power, then emissions are reduced compared to the main engine, but zero emissions are not achieved and additional system complexity is required
Solution Approach 1:
The patent replaces the mechanical coupling between the main engine and auxiliary loads with an electrical system. The APU generates electrical power that can be used to drive electric motors for various auxiliary loads, eliminating the need for mechanical transmissions and reducing emissions by allowing complete engine shutdown.
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 solution reduces emissions and fuel consumption by allowing the main engine to shut down during rest periods, while maintaining cabin comfort through efficient power distribution, and is cost-effective and durable enough for long-term use in line-haul trucks.
Implementation Method 1
an auxiliary system that includes an air conditioning compressor with a jackshaft mounted on a hub of the compressor... and a hydrogen fuel cell unit that provides power to the compressor
Implementation Method 2
an electric motor connected to the jackshaft by a belt for the motor, wherein the electric motor has a drive shaft and a pulley rigidly secured thereon
Data Source
AI summary
According to one form of the invention, an auxiliary system is provided for supplying air conditioning to the cabin of a truck. The system includes an air conditioning compressor having a jackshaft mounted on a hub of the compressor. The system further includes an electric motor connected to the jackshaft by a belt for the motor, wherein the electric motor has a drive shaft and a pulley rigidly secured thereon, i.e., with no clutch and with no provision for slippage of the pulley relative to the drive shaft. The jackshaft has a pulley thereon for the electric motor drive. An end of the jackshaft that is not proximate to the compressor is rotatably held by a bearing and a bearing bracket in order to increase capability of the jackshaft to withstand side loading.