Tuesday, 20 September 2016

Volkswagen Group, 1.6 CAYC diesel engine, exhaust gas recirculation system - EGR.

Diesel engine 1.6 CAYC
Technical specifications.
4 cylinder, 1,598 cm³ turbo-diesel engine developed by the VAG group.
The engine has a double overhead camshaft and 16 valves.
Common rail direct injection system with piezoelectric injectors.
Charge air system with variable geometry turbocharger and intercooler.
Catalytic converter with particulate filter.
EGR solenoid valve with exhaust gas recirculation cooling.
Meets Euro 5 anti-pollution standard.

Torque and power curves:

Exhaust gas recirculation EGR.
The purpose is to reduce nitrogen oxide emissions. A part of the exhaust gases are fed back into the combustion process. The engine control unit regulates the flow of recirculated exhaust gases, while taking into consideration the engine speed, the amount of aspirated air, the aspirated air temperature, amount injected and air pressure.

Exhaust gas recirculation schematic.

EGR Valve opening motor
This is located at the bottom and rear of the engine, at the outlet of the heat exchanger for the recirculated exhaust gases. The control unit controls the operation of the gas recirculation valve motor.

The EGR system comprises a motor whose shaft moves the plate valve in the longitudinal direction. Depending on the degree of opening of the valve, more or less exhaust gas will pass.

The control unit controls the amount of gases recirculating at any time, by acting on the gear motor with a fixed frequency and variable duty cycle signal.

 A sensor informs the control unit on the position of the EGR valve. It is supplied with 5 V and connected to the unit's ground.

Gas recirculation cooler
This is fastened to the engine block and located under the turbocharger, it forms a single unit with the EGR valve. This is a heat exchanger that cools the exhaust gases by means of the engine coolant. In this way, nitrogen oxides emitted to the atmosphere are reduced.

A pneumatic valve actuates the gas bypass flap. When the coolant temperature is lower than 30 °C, the gas does not pass through the exchanger. When the coolant reaches 30°C, the gas is allowed to flow to the exchanger.

Additional water pump for cooling the exhaust gases
This is located at the front lower part of the engine, next to the oil sump. This is an electric pump that sucks cold coolant from the main engine radiator and pumps it to the exhaust gas heat exchanger. This is supplied with power on switching on the ignition and is managed by the control unit.

1 comment:

  1. Consise description. What about effect on mpg?


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