Urea Dosing Device Cooling Bypass for Frozen Storage
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Solution Overview
Problem
Existing medium feeding systems for exhaust gas purification face issues with freezing reducing agents at low temperatures, leading to potential damage from thermal stress due to prolonged thawing times of the medium in the storage vessel, which can block the medium circuit and prevent adequate cooling of the dosing device.
Innovation Solution
Incorporating an additional fluid connection or bypass line between the flow and return lines, allowing for medium circulation and cooling of the dosing device independently of the storage vessel's thawing status, ensuring continuous heat dissipation and preventing thermal overload.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If the medium flows through the storage vessel for cooling the dosing device, then the dosing device is adequately cooled, but the medium circuit is blocked by frozen medium in the storage vessel at low temperatures
Solution Approach 1:
The patent divides the medium circuit into two independent pathways: the original pathway through the storage vessel and a new bypass pathway. This segmentation allows the system to switch between pathways based on operating conditions, enabling the dosing device to be cooled even when the storage vessel contains frozen medium that blocks the original pathway.
Solution Approach 2:
The bypass line acts as an intermediary pathway that mediates between the flow line and return line, providing an alternative route for medium circulation when the storage vessel pathway is blocked. This intermediary pathway ensures continuous cooling capability without requiring the storage vessel to be thawed.
2Object-affected harmful factors
If insulation is increased to prevent medium freezing, then freezing protection is improved, but heat dissipation capability deteriorates
Solution Approach 1:
The patent implements a dynamic switching capability between two circulation pathways. The bypass line with its throttle device allows the system to adapt to changing thermal conditions, enabling adequate cooling of the dosing device even when the storage vessel requires insulation to prevent freezing.
Solution Approach 2:
The throttle device in the bypass line allows for flow rate adjustment, enabling the system to optimize the balance between preventing medium freezing in the storage vessel and ensuring adequate heat dissipation from the dosing device by controlling medium circulation parameters.
3Temperature
If the medium volume in the storage vessel is large for sufficient cooling capacity, then cooling performance is improved, but thawing time increases significantly at low temperatures
Solution Approach 1:
The patent segments the cooling function between the storage vessel medium (large volume for thermal mass) and the bypass line circulation (provides immediate cooling pathway). This allows the system to maintain adequate cooling capacity through the bypass pathway without requiring the entire large volume in the storage vessel to be thawed.
Solution Approach 2:
The bypass line ensures continuous medium circulation and cooling of the dosing device even when the storage vessel is frozen. The throttle device maintains continuous flow through the bypass pathway, eliminating interruptions in the cooling function during thawing periods.
4Reliability
If a bypass line is added to enable alternative circulation, then system reliability is improved, but device complexity increases
Solution Approach 1:
The bypass line serves as a simple intermediary connection between the flow line and return line, providing redundancy without significantly complicating the overall system architecture. The throttle device adds minimal complexity while enabling reliable operation under varying conditions.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This solution ensures the dosing device remains adequately cooled and protected from thermal damage by maintaining a medium flow through the bypass line even when the storage vessel is blocked by frozen medium, preventing damage from prolonged thawing times.
Implementation Method 1
the medium can be circulated for cooling the dosing device along the supply line... Adequate cooling of the dosing device is thus ensured independently of the thawing time of a frozen media volume present in the storage vessel
Data Source
Figure 1
AI summary
The invention relates to a supply system (1) for supplying urea, in particular for an exhaust-gas purification device for the treatment of exhaust gases of an internal combustion engine, having a storage vessel (5) for the medium, having a dosing device (7) for dosing the medium in particular into an exhaust line (3) of an internal combustion engine, and having a supply line (9) which comprises a feed line (11) for supplying the medium to the dosing device (7) and a return line (13) for returning the medium from the dosing device (7) into the storage vessel (5), wherein the dosing device (7) is designed such that, during the operation of the supply system (1), for the purpose of cooling of the medium, flow can be caused to pass through said dosing device from a feed port (17) to a return port (19) of the dosing device (7). It is provided here that the supply line (9) comprises an additional fluid connection (23), such as a bypass, between the feed line (11) and the return line (13), wherein the additional fluid connection (23) issues into the feed line (11) upstream of the feed port (17) of the dosing device (7) and issues into the return line (13) downstream of the return port (19) of the dosing device (7). In this way, damage caused by elevated thermal loading in the event of the fluid circuit being blocked by frozen fluid in the region of the storage vessel is prevented.