Exhaust gas control system
AssigneeToyota Jidosha Kabushiki Kaisha
InventorsShinya ASAURA, Masaaki SATO, Ryohei ONO, Yuji MIYOSHI
Life of this patent
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Abstract
A first fuel addition valve disposed in a portion of a first exhaust passage upstream from a first upstream purification device, a first urea addition valve disposed in a portion of the first exhaust passage between the first upstream purification device and a first downstream purification device, and a first valve cooling passage configured such that i) refrigerant passes the first urea addition valve and the first fuel addition valve in order, and ii) the refrigerant cools the first fuel addition valve after the refrigerant cools the first urea addition valve.
Claims14
An exhaust gas control system comprising:
- a first upstream purification device disposed in a first exhaust passage of an internal combustion engine, that is a compression ignition engine, the internal combustion engine configured to be operated to perform lean combustion, the first upstream purification device including an oxidation catalyst;
- a first downstream purification device disposed in a portion of the first exhaust passage downstream from the first upstream purification device, the first downstream purification device including a selective catalytic reduction catalyst;
- a first fuel addition valve disposed in a portion of the first exhaust passage upstream from the first upstream purification device, the first fuel addition valve configured to add fuel into exhaust gas;
- a first urea addition valve disposed in a portion of the first exhaust passage between the first upstream purification device and the first downstream purification device, the first urea addition valve configured to add urea aqueous solution into the exhaust gas;
- and
- a first valve cooling passage configured such that
- i) refrigerant passes the first urea addition valve and the first fuel addition valve in order, and
- ii) the refrigerant cools the first fuel addition valve after the refrigerant cools the first urea addition valve.
An exhaust gas control system, comprising:
- a first exhaust passage;
- a second exhaust passage;
- a third exhaust passage connecting to a confluence of the first exhaust passage and the second exhaust passage;
- a first upstream purification device disposed in the first exhaust passage of an internal combustion engine that is a compression ignition engine, the internal combustion engine configured to be operated to perform lean combustion;
- a second upstream purification device disposed in the second exhaust passage of the internal combustion engine:
- a first downstream purification device disposed in the third exhaust passage;
- a first fuel addition valve disposed in a portion of the first exhaust passage upstream from the first upstream purification device;
- a second fuel addition valve disposed in a portion of the second exhaust passage upstream from the second upstream purification device;
- a first urea addition valve disposed in the third exhaust passage upstream from the first downstream purification device;
- a first valve cooling passage configured such that refrigerant passes the first urea addition valve;
- a second valve cooling passage configured such that a part of the refrigerant that has passed the first urea addition valve passes the first fuel addition valve;
- and
- a third valve cooling passage configured such that the remaining part of the refrigerant that has passed the first urea addition valve passes the second fuel addition valve, and
- the first valve cooling passage, the second valve cooling passage and the third valve cooling passage being configured such that
- i) the part of the refrigerant that has cooled the first urea addition valve cools the first fuel addition valve subsequent to the first urea addition valve, and
- ii) the remaining part of the refrigerant cools the second fuel addition valve subsequent to the first urea addition valve.
Dependencies are inferred from the claim text.