Method for operating cooling and heating circuit for e.g. large passenger car, involves maintaining effective combustion fresh air mass flow smaller than reference fresh air mass flow for reducing cabin heat power deficit

摘要

The method involves shifting fuel injection timing. Effective combustion fresh air mass flow is maintained 50 percent smaller than reference fresh air mass flow for reducing cabin heat power deficit at engine speed below 1500 1/min during temporary heating after activation of external gas recirculation (EGR) by an EGR control valve (14) such that a charging gas cooler (31k) is deactivated. The reference fresh air mass flow is calculated by using specific equation relating piston displacement, engine speed and surrounding air density. Independent claims are also included for the following: (1) a device for demand-wise increasing of coolant-side waste heat in a motor vehicle, comprising a charging gas cooler (2) a device for operating a cooling and heating circuit for a motor vehicle, comprising an EGR control valve.