Toyota: Prius Phv's Heating System Recompresses Coolant

Toyota: Prius PHV's Heating System Recompresses CoolantToyota Industries Corp announced Feb 17, 2017, that it has developed a motor-driven compressor for recompressing part of compressed coolant.
The compressor, "ESBG27," was employed for the "Prius PHV," which Toyota Motor Corp released Feb 15, 2017. It enables to warm the interior space of the vehicle with a heat pump without using the engine at a temperature below zero. As a result, it reduces fuel consumption and increases EV driving range.

A heat pump-based heater increases efficiency by using the heat of the atmosphere. When the outdoor temperature is low, the amount of usable heat is small, lowering its heating capability. This time, Toyota Industries realized "Gas Injection Cycle," which, after compressing coolant and warming the interior space, injects part of the coolant into a branch path and recompresses it.

According to Toyota Industries, this is the first time in the world that a motor-driven compressor using the Gas Injection Cycle has been employed for a mass-produced car. By making improvements to the branch path, the new method increases the amount of recompressed coolant while increasing compression efficiency and reducing vibration. As a result, the company improved heating capability at a low temperature by about 30%.