Description:Complete Specification:
The following specification describes and ascertains the nature of this invention and the manner in which it is to be performed:

Field of the invention
[0001] The present disclosure relates to a diesel exhaust fluid (DEF) system to measure a temperature of an exhaust fluid .
[0002] Background of the invention
[0003] Modern diesel vehicles that are equipped with selective catalytic reduction use a diesel exhaust fluid (DEF) for removal and reduction of nitrous oxides. The DEF typically comprises high purity urea dissolved and suspended within de-ionized water. This solution of urea in demineralized water is commonly known as Adblue.

[0004] The DEF (AdBlue) is stored in the manufacturer’s original container and kept in a cool, covered area with good ventilation and out of direct sunlight to prevent water loss due to evaporation. Typically, the DEF (AdBlue) freezes at -11.5 deg. When it is thawed, it returns to its initial quality. When the vehicle is switched ON, a supply module (SM) supplies DEF (AdBlue) to a dosing module for the exhaust gas treatment. However, due to frozen DEF (AdBlue), the supply is restricted till a heater melts & clears the frozen AdBlue in the flow path of the supply module.

[0005] In existing systems, there are no systems that can effectively detect the AdBlue temperature to understand the fluid condition. The prior art US2022127988 AA discloses a first temperature sensor positioned within the exhaust fluid chamber and structured to provide first temperature information indicative of a first temperature, and a second temperature sensor positioned within the exhaust fluid chamber and structured to provide second temperature information indicative of a second temperature. The systems and apparatuses further include one or more processing circuits including one or more memory devices coupled to one or more processors, the one or more memory devices configured to store instructions thereon that, when executed by the one or more processors, cause the one or more processors to provide energy to a heating system based on the first temperature information and the second temperature information.

[0006] In the present disclosure, an Infrared temperature sensor is soldered on to a PCB, said PCB attached to a pump module. The IR sensor is between the PCB and the exhaust fluid (AdBlue) tank. Based on the distance between the PCB and the housing of the DEF chamber and the thickness of the housing, the temperature of Adblue is measured. This allows for the DEF temperature to be measured in the existing DEF system designs and improves the dosing efficiency of the DEF into the SCR.
[0007] Brief description of the accompanying drawings
An embodiment of the invention is described with reference to the following accompanying drawings:
[0008] Figure 1 depicts a diesel exhaust fluid (DEF) system to measure a temperature of an exhaust fluid.
[0009] Figure 2 depicts a flowchart for a method to measure a temperature of an exhaust fluid in a diesel exhaust fluid (DEF) system.

Detailed description of the drawings:
[0010] The present disclosure provides a system and a method to measure a temperature of an exhaust fluid.

[0011] The present invention will now be described by way of example, with reference to accompanying drawings. Throughout all the figures, same or corresponding elements may generally be indicated by same reference numerals. These depicted embodiments are to be understood as illustrative of the invention and not as limiting in any way. It should also be understood that the figures are not necessarily to scale and that the embodiments are sometimes illustrated by graphic symbols, phantom lines, diagrammatic representations, and fragmentary views. In predetermined instances, details which are not necessary for an understanding of the present invention, or which render other details difficult to perceive may have.

[0012] Referring to Figure 1, the same depicts a diesel exhaust fluid (DEF) system (10) to measure a temperature of an exhaust fluid. The DEF system comprises a pump module (1), an exhaust fluid chamber (2) and a Printed Circuit board (PCB)(3). The DEF chamber has a housing (5) of a pre-defined thickness. The PCB (3) is attached to the pump module (2). An infrared (IR) temperature sensor (4) soldered on to the PCB (3). Said IR temperature sensor (4) is adapted to measure the temperature of the exhaust fluid.

[0013] The IR temperature sensor measures the temperature of the exhaust fluid based on the pre-defined thickness of the housing, and a pre-defined distance between the housing of the exhaust fluid chamber and the PCB.
[0014] A temperature of the DEF chamber housing surface is measured to detect the DEF temperature indirectly (without direct contact). The infrared (IR) temperature sensor senses the temperature by projecting an infrared beam (6) over the AdBlue housing surface and receiving an output signal. The output signal will be sent to an electronic control unit of a vehicle adapted to control the exhaust air treatment system of the vehicle. Since the IR sensor will only detect the surface temperature of the AdBlue housing, the difference in temperature between housing surface and AdBlue will be calibrated in the electronic control unit.
[0015] Referring to figure 2, the same depicts a flowchart for a method to measure a temperature of an exhaust fluid in a diesel exhaust fluid (DEF) system, said DEF system comprises a pump module, an exhaust fluid chamber of a pre-defined thickness and a Printed Circuit board (PCB) attached to the pump module as described above. It is to be understood that a system to implement the present method has been described in Figure 1. The method comprises the first step (101) of soldering IR temperature sensor on the PCB, followed by step (102) of measuring the temperature of the exhaust fluid.
[0016] Measuring the temperature of the exhaust fluid, by the temperature measuring device is done based on a pre-defined thickness of the housing, and a pre-defined distance between the housing of the exhaust fluid chamber and the PCB.

[0017] Advantageously in the present invention, the proposed DEF system provides improved sensing accuracy of the exhaust fluid. Since IR temperature sensor is contactless process, the existing designs can adopt the proposed system and method to measure the exhaust fluid temperature. The IR Temperature sensor can be easily soldered on to the PCB. Further, existing IR temperature sensors offer high sensing accuracy and can be operated under the temperature range used in supply module of the DEF system. (- 40º C to 85º C). Further the IR temperature sensor can be adopted for different material based on the emissivity of the said material.
, Claims:WE CLAIM:

1. A Diesel Exhaust Fluid (DEF) system (10) to measure a temperature of an exhaust fluid, said DEF comprising:
-a pump module(1),
-an exhaust fluid chamber (2) with a housing(5) of a pre-defined thickness, and
-a Printed Circuit board (PCB) (3) attached to the pump module(1),

characterized in the DEF,
an infrared (IR) temperature sensor (4) soldered on to the PCB(3), said IR temperature sensor (4) adapted to measure the temperature of the exhaust fluid.

2. The DEF system(10) as claimed in Claim 1, wherein the IR temperature sensor measures the temperature of the exhaust fluid based on:
-the pre-defined thickness of the housing (5), and
-a pre-defined distance between the housing(5) of the exhaust fluid chamber and the PCB(3).

3. A method(100) to measure a temperature of an exhaust fluid in a diesel exhaust fluid (DEF) system, said DEF comprising
-a pump module,
-an exhaust fluid chamber with a housing of a pre-defined thickness, and
-a Printed Circuit board (PCB) attached to the pump module,

the method characterized by:
-soldering an IR temperature sensor on the PCB(101); and
-measuring the temperature of the exhaust fluid (102).

4. The method (100) as claimed in Claim 3, wherein, measuring the temperature of the exhaust fluid, by the temperature measuring device based on:
-a pre-defined thickness of the housing, and
-a pre-defined distance between the housing of the exhaust fluid chamber and the PCB.