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Pierburg introduces air conditioning components specifically for EVs

In vehicles with a conventional internal combustion engine, the a/c compressor is usually driven via a pulley and the V-belt but in electric vehicles, this mechanism is not available. Here, the a/c compressor is driven by an electric motor that is integrated into the vehicle’s high-voltage network. Pierburg GmbH has developed an electric a/c compressor (eCC) that incorporates the supplier’s many years of experience in the field of mechatronic components.

Electric ac compressor eCC_elektrischer Klimakompressor

The new unit is of compact design so that it can fit in the usual installation spaces and serves the regular voltage levels HV2 and HV3. The three modules—mechanical compressor unit, electric motor and power electronics—are modularly integrated.

During development, particular emphasis was placed on low weight and high operating efficiency. This ensures economical power management with the limited electrical energy available from the high-voltage storage unit in the vehicle.

The design of the machine allows not only classical air conditioning operation at warm outside temperatures but also heat pump operation at low ones. By using a heat pump to heat the driver’s cab, the energy flow from the high-voltage storage unit can be reduced as required, thus increasing the vehicle’s travel range.

A further development focus was the low noise of the compressor, since its sound and vibrations are perceived as disturbing by the driver and occupants.

In addition, Pierburg developed an electronically controlled expansion valve for the refrigerant circuit. The new valve is usually mounted on an evaporator or chiller and controls the refrigerant flow; these heat exchangers are suitable for use in air conditioning, cooling battery packs or electric driveline components.

Thanks to its compact design, the valve developed by Pierburg can be completely integrated into heat exchangers; the refrigerant flow can be regulated as required by means of an electric actuator, thus increasing the overall efficiency of the system.

Comments

Engineer-Poet

The casing still has joints and fasteners, meaning gaskets which can leak.  The next step is to put the compressor in a hermetically sealed, welded can like most electric A/C hardware uses.  The electronics can be integrated either inside or outside the hermetic seal.

Thomas Pedersen

In a misguided effort to conserve fuel, I drove almost 6 months with the A/C off, resulting in the gaskets drying out and leaking out the refrigerant. And since R134A has a GWP (global warming potential) of 1400, the re-fill corresponded to about 700 kg of CO2 or 200 kg of diesel. Probably 10-50 times more than I saved.

Btw, my compressor is electrically driven.

Only if car OEMs accept to have the entire refrigerant circuit mounted as a single unit incl. both heat exchangers, can the unit realistically be completely sealed. I believe welding and soldering of pipes after installation into the engine bay is not something car factories would like to deal with..?

Engineer-Poet

One of the ways carmakers have made A/C evaporators is by vacuum induction brazing.  They're old pros at this stuff.  Sweat-soldering of joints on the production line doesn't sound like something that would slow them down much; just pre-solder the mating surfaces to an interference fit, squeeze together using some kind of tool during installation, and then heat the joint to seal it.

If your A/C compressor is electric, but it still has a shaft seal, it sounds very much like the mfgr is Doing It Wrong.

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