摘要 |
One of the inventors' concepts relates to controlling a temperature of a diesel engine exhaust aftertreatment device, such as a DPF or a fuel reformer, in which combustion is taking place. The concept is to inject reductant to combust in an upstream device, thereby removing oxygen in the exhaust and limiting combustion in the downstream device. The same total amount of heat may be generated, but the distribution is different and limits temperatures in the downstream device. The temperature limiting effect may be through one or more of the thermal storage capacity of the upstream device, the additional heat loss to the surroundings due to higher temperatures upstream in the exhaust system, or the benefit of a more uniform distribution of heat in the downstream device, which mitigates local hot spots. This concept may be used in a temperature control system. |