Denso’s got a solution.
Wayne Gerdes - CleanMPG
- Sept. 14, 2012
Denso’s CS Evaporator system and the cutaway.
In a release late last week, DENSO has developed a Cold Storage (CS) Evaporator, which is supposed to limit the increase in vehicle cabin temperature during an idle stop when stop/start hardware is engaged. The CS Evaporator is equipped with a cold insulator, located in the heat exchanging area, which stores cold energy to be used to cool in-vehicle cabin air while the engine and air-conditioning cycle is off in the idle-stop state.
An evaporator is driven by engine power to provide the “cold”. The cold refrigerant exchanges heat with warm air to send cooled or dehumidified air to the cabin. For conventional A/C, when the engine stops during an idle-stop mode, the A/C stops although in some Start/Stop systems; a low fan setting may continue recalculating cooler air until such time a temperature rise of a given amount is reached which restarts the engine even if still at a stop.
On higher temperature days, Auto Start/Stop may not engage at all in order to cool the cabin!
DENSO’s CS Evaporators
From the Denso PR, the CS Evaporator has the same size of a conventional evaporator but it can store cold energy more quickly and discharge cooled air more slowly. DENSO did it by installing a closed case with inner fins and a cold insulation inside. The cold insulation case is placed between refrigerant tubes, which the cold insulator directly and efficiently extracts cold energy from during the A/C cycle. When the A/C cycle is stopped, cooled air is slowly released from the cold insulation container via the outer fins connected to the refrigerant tubes.
With this system, storing “cold” can be completed even in a relatively short time of vehicle travel and cooled air can be supplied to the cabin for a long period of time.