Bosch presenting new heat pump EV thermal management system at IAA; up to 25% increase in effective range
At IAA next week, automotive supplier Bosch is presenting a new heat-pump-based thermal management system for EVs that it says can enable an increase in effective range of up to 25% without modifications to the battery.
In battery-driven powertrains, heating and cooling can play a significantly greater role than in gasoline or diesel engines, since without a combustion engine, the vehicle does not have a generous supply of heat. If the passenger compartment is heated using a purely electrical system drawing its power from the battery, range can be significantly reduced. As a result, there has been interest in the industry about the use of heat pumps as a lower energy-intensity solution.
For example, Nissan adopted a heat pump for the LEAF in 2014, and Volkswagen is using a heat pump is the US e-Golf as an add-on module to the electric heater (earlier post). In 2011, ARPA-E awarded Pacific Northwest National Laboratory (PNNL) funding to develop a new electric power driven adsorption cycle for a highly efficient heat pump for EVs. (Earlier post.)
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.
Most of the individual components used in this approach are already to be found in commercially available applications, Bosch said.