VASA has been saying it for some time, but now Denso sees thermal management as one of its most important focus areas.
Denso CEO of thermal systems in Europe, the Middle East and Africa, Marco Di Rao, predicts that heat pumps and thermal management will be
“key enablers of the electrification of mobility”.
“First of all, a heat pump system for an electric vehicle has multiple roles,” he said.
“It not only controls the temperature inside the cabin and the battery, both in summer and winter, but also the electric gear which is sensitive to high temperature levels.”
Denso claims its heat pump technology can provide cabin warmth even at ambient temperatures of -10°C.
Being at a lower temperature than ambient, refrigerant can absorb heat from outside air. However the lower the ambient temperature,
To overcome the lower density of vaporised refrigerant at low ambients and therefore its ability to absorb heat from cool outside air, Denso’s heat pump technology extracts high-density vapour and injects it into the electrically driven compressor to increase the mass flow rate of circulating refrigerant and help boost heating performance.
By decompressing the refrigerant in two steps (medium and low pressure), the refrigerant becomes a mixture of vapour and liquid.
To exploit this, Denso has developed a small, high-efficiency gas-liquid separator to extract the high density refrigerant vapour from this mix.
Energy used to drive the compressor (the same one used for air-conditioning in warmer weather) is effectively added to the amount taken from the environment, providing heating to the cabin.
This method is particularly useful in electric vehicles that cannot rely on a hot-running internal combustion engine to help keep the cabin warm in winter.
It is also much more energy efficient than conventional electric heaters and results in better battery range.
Mr Di Rao said Denso’s heat pump helps to “resolve the ‘either/or’ dilemma of comfort versus range.”
“Any solution that allows for the more efficient use of the energy stored in the car battery is undoubtedly greener and, ultimately, benefits society as a whole,” he said. “You won’t need to compromise on range or comfort.”
Denso says this breakthrough also makes heat pumps easier to install.