Bosch will be unveiling a new heat-pump-based thermal management system designed specifically for electric vehicles (EVs) that the company claims can boost effective range by up to 25% (without any changes to the battery) at IAA in a few days.
The claimed boost in effective range is, of course, reportedly down to a more efficient use/redistribution of the relatively sparse heat generated by electric power trains. As anyone can surmise, combustion engines generate a lot of heat — and there’s not much reason to burn fuel specifically for generating heat during the winter in conventional vehicles. This is in contrast to EVs, where heat needs for be generated from battery stores if one wants a warm interior during the winter. This, understandably, lowers the effective range of the EV in question.
Heat pumps in EVs aren’t actually new, though, it should be remembered — a number of models, including the Nissan LEAF (as of 2014), make use of them.
Green Car Congress provides more information:
In the publicly funded GaTE project (integrated thermal management in electric vehicles), Bosch, Mahle, Behr, and other companies developed a basis for optimized thermal management. Bosch’s new thermal management system distributes heat and cold solely on the basis of the vehicle’s coolant fluid, using a combination of a heat pump with coolant pumps and valves. With the new vehicle thermal management system, a heat pump with an electrical rating of 1,000 watts will generate heat equivalent to an output of 2,000 to 3,000 watts. Conventional heaters used in hybrids and electric vehicles are only half as effective, Bosch said.
Bosch’s system features precisely controllable pumps and valves which collect heat and cold at source and transport them to where they are needed. The need for heating and cooling is additionally reduced by the use of waste heat from the electric motor and the power electronics, plus controlled air circulation that draws moisture from the air. The pump makes use of the small amount of heat that is generated in an electric vehicle. For example, heat is released when supplying the electric motor with electricity. When braking energy is converted into electricity and fed into the battery, usable heat is again created. This is also the case when the battery has to be cooled in order to remain within the optimum operating window.
According to Bosch reps, the majority of the individual components used in the new system are already in use commercially in various different ways.
Image Credit: Bosch
I might not be understanding the picture or the mechanics of this heat pump system, but in the picture, it looks like it’s sending heat TO the battery- Don’t you want to be removing heat from the battery so it doesn’t overheat?
The figure is drawn for very cold conditions where heat is needed both by the cabin and the battery. There might be intermediate conditions where the battery gets too warm and needs cooling, but usually the cabin will also.
This is a great development, and one can only marvel that Tesla has not seen fit to implement a reversible heat pump to help make the available energy go farther and preserve driving range in cold weather.