报告：混合动力重型柴油动力系统开发（卡特彼勒）

执行摘要

卡特彼勒（Caterpillar）在该非道路应用混合动力重型柴油动力系统项目中，开发并演示了一种重型混合动力系统，该系统由排量减小30%的柴油发动机和FEAD前端附件驱动（front-end accessory drive）组成，前端附件驱动包含高速飞轮（HSFW：high-speed flywheel）储能系统、机械驱动涡轮增压器（SuperTurbo）和电动发电机组（MGU：motor-generator units）。

   

高效核心13L发动机与混合动力元件在各种越野设备和瞬态工作循环中进行了物理验证，最终目标是以与该概念动力系统将取代的18L柴油发动机相同的瞬态响应，将效率提高17%。

   

该项目最终在高性能试验室中对高效动力系统进行了物理演示，该试验室配有发动机、所有混合动力装置、控制装置以及所需的性能和排放测量。

   

表1总结了关键混合系统组件和子系统在各种瞬态循环中的效率贡献。作为提醒，表中显示的范围反映了所测试的三种不同的设备应用。此外，对于一些子系统，只显示了仿真结果——减少的冷却系统寄生不在该计划的范围内，而其他两个项目由于时间和资源的限制而没有经过物理验证。然而，在每一种情况下，都使用了根据可用的物理验证数据进行校准的近似值。

项目结论：

基于物理验证和严格的系统模拟相结合，可以得出以下项目结论：

• 所开发的混合动力H2D2动力系统的效率提高幅度为10.5-25.6%，中点为17.9%。这一结果满足了效率提高17%±2的项目目标。    

• 验证了从800到1800rpm的约1-1.5秒响应时间的瞬态负载响应。

• HSFW系统经过验证，可在12000牛米/秒的斜升速率下实现110kW的峰值辅助。

• 通过瞬态NRTC测试，验证了动力系统能够满足美国环保局Tier 4最终非道路排放要求。

• 通过结构和热流体仿真验证了概念13L发动机的耐久性，使其能够在排量减小30%的应用中连续运行。

• 总拥有成本（TCO）分析发现，核心13L发动机将立即收回成本。

• 采用启动/停止将在不到一年的时间内获得回报，

• 全混合动力系统的投资回报期为三年。

Executive Summary

In this program, a heavy-duty hybrid powersystem, consisting of a 30% downsized diesel engine anda front-end accessory drive (FEAD) incorporating a high-speed flywheel (HSFW) energy storage system, amechanical-drive turbocharger (SuperTurbo), and motor-generator units (MGU) was developed anddemonstrated. The high efficiency core 13L engine coupled with the hybrid elements was physicallyvalidated across various off-road machine and transient work cycles with the ultimate goal ofdemonstrating 17% efficiency improvement with equivalent transient response as the 18L diesel enginethis concept powersystem would replace. The project culminated in a physical demonstration of the highefficiencypowersystem in a high-capability test cell with the engine, all the hybrid devices, controls, andrequired performance and emissions measurements.Table 1 summarizes the efficiency contributions from key hybrid system components and subsystemsagainst various transient cycles. As a reminder the ranges show in the table are reflective of the threedifferent machine applications examined. Additionally, for some subsystems, only simulation results areshown – the reduced cooling system parasitic was out-of-scope for the program, and the other two itemswere not physically validated due to time and resources constraints. However, in each of these casessimulations that were calibrated against available physical validation data were used.              

Based on the combination of physical validation and rigorous system simulation, the followingprogram conclusions may be drawn:

• The developed hybrid H2D2 powersystem demonstrated a range of efficiency improvement of 10.5- 25.6%, with a midpoint of 17.9%o This result met the program goal of 17%±2 efficiency improvement.

• Transient load response on the order of ~1-1.5 second response times from 800 - 1800rpm wasvalidated.· The HSFW system was validated to achieve peak assisting of 110kW at 12,000 Nm/sec ramp rates.

• The powersystem was validated to be capable of meeting U.S. EPA Tier 4 Final off-road emissionsthrough transient NRTC testing    

• As required for Go/No-Go Milestone #2, the durability of the concept 13L engine was validatedthrough structural and thermofluid simulations to be acceptable for continuous operation in the30% downsized applications.

• A Total Cost of Ownership (TCO) analysis and found that the core 13L engine would pay backimmediately.

• Adoption of start/stop would pay back in less than one year, and

• The full hybrid system payback was three years.