Good News Notes:
“GM confirmed Monday that it plans to include heat-pump technology in all of its current and upcoming Ultium-platform electric vehicles.
That includes the Hummer EV now being delivered and the soon-arriving Cadillac Lyriq, plus many more to arrive in the next several years. In them, the tech will help recover low-level waste heat in ways that can add up in meaningful ways—bringing them quicker acceleration, faster charging, and a longer range.
The system is based around an automotive-grade heat pump that captures and recoups that waste heat. Like the systems other automakers like Tesla use (or Toyota, with the illustration below), the one in GM EVs employs a compressor-and-evaporator component system and a specially chosen refrigerant that undergoes a phase change. A physical reaction pays off in the release of energy as it goes from gas to liquid—to in effect amplify whatever energy it can scavenge along the way.
That extra can go toward cabin heating, low-level electrical functions, or even preconditioning of the battery—potentially extending range by as much as 10%.
According to GM director of electrification Tim Grewe, the Ultium platform was envisioned from the start to be a building-block strategy allowing small consumer EVs like the Chevy Blazer EV (and Equinox EV) on up to large commercial vans. GM claims it can help speed up charging and acceleration and extend range.
The Ultium platform strategy is quite a bit different than that of the thermal system of the current Bolt EV, the executives explained, as it uses the heat-pump approach as a way of consolidating, and simplifying the rest of the system.
The heat pump doesn’t add mass—even in comparing the larger Ultium models with the Bolt EV—confirmed the project manager for the system Lawrence Ziehr. “It’s just a smarter way of connecting the systems.”
Rather than adding more cooling circuits, as was done in the Bolt EV, you can use the drive unit as a cooler for the battery and “not be slave to the environment of the ambient temperature,” as Grewe put it. The Ultium vehicles have one resistive coolant heater, versus the Bolt EV’s two, and it also eliminates the need for a standalone A/C compressor. …”