CUMMINS UL2.2 Urea Dosing System

Urea pump-Features

Urea pump design

➢ Volumetric liquid pump design

➢ Diaphragm design separates fluid from motor

➢ Speed ​​of speed-adjusting motor 800-3500RPM

Function

➢ Provide pressure to injection valve

➢ 30 micron main filter element filters urea (maintenance parts)

➢ 190 micron urea inlet filter element prevents impurities from entering

Antifreeze design (antifreeze rubber sleeve)

➢ When the pump is turned off, the pressure in the pump will decay naturally (about 15 minutes)

➢ The main filter element will not be damaged by freezing

➢ The urea pump can withstand the volume expansion of urea after freezing

Thawing ability

➢ Coolant from the engine after heating circulates in the urea pump to thaw it

➢ Defrost the urea in the pump directly through the heat conduction characteristics of the metal structure

Injection valve-structure

Main components

➢ External parts – urea inlet connector, urea return connector, plastic housing, mounting bolts, stainless steel body, nozzle, etc.

➢ Internal parts – pressure sensor, injection solenoid valve, valve seat, urea inlet filter, return flow limiting hole, etc.

Working principle

➢ Inject a certain amount of urea into the post-treatment system according to actual needs.

➢ Achieve the atomization effect of injection.

➢ Ensure the return of liquid urea through the return hole to achieve the cooling effect.

Features

➢ The inlet filter has a larger filtration area and a longer maintenance interval.

➢ Optimized antifreeze rubber sleeve, better anti-freezing expansion ability.

➢ Use graphite gaskets and metal gaskets for sealing and insulation, which can withstand high temperatures of 150℃.

Urea tank and level temperature quality sensor

Cummins Emission Solutions’ Urea Tank System provides customers with the convenience of a fully packaged aftertreatment system for Selective Catalytic Reduction (SCR) technology. The Urea Tank System

portfolio includes a range of urea tanks and header assemblies equipped with required sensors, as well as a wide range of urea lines to meet the installation needs of many applications.

Urea level temperature sensor

Tank assembly

Tank assembly benefits include:

• Robust urea-quality sensing technology, designed with the required vibration durability to withstand rough terrain and steep gradients
• Leading high-efficiency filtration, improving system reliability and extending service intervals
• Temperature-sensing technology, providing freezeprevention control
• Tank ventilation, allowing for appropriate tank expansion and compression, providing flexibility for operation across a wide range of altitudes and environments

CUMMINS UL 2.2 Workflow

•  The key switch is turned on, the system self-checks, thawing is completed, and the pre-injection command is waiting.
•  After the pre-injection conditions are met, the urea pump starts to work and build pressure. After the open-loop pressure is built, it enters closed-loop control. The motor continues to work to maintain pressure and cool the injection valve.
•  In the closed-loop control state, the motor continues to work to keep the pressure within a certain range; ECM controls the injection amount of the injection valve as needed.
•  The urea pump motor stops working; the pressure in the pump is released automatically.
• The ECM gives a delayed cooling nozzle instruction.And the urea pump motor stops working.