Claims:We Claim

1. A system for diesel exhaust fluid (DEF) quality measurement, the system comprising:
a tank for holding diesel exhaust fluid therein;
a supply module connected to the tank for refilling the diesel exhaust fluid;
a flange welded to the tank;
a sensor secured to the flange for measurement of the quality of diesel exhaust fluid,
characterized in that the sensor comprises heating element configured inside housing to heat the localized diesel exhaust fluid of the tank thereby providing immediate reading of the quality of the diesel exhaust fluid.

2. The system as claimed in claim 1, wherein the heating element is resistor.

3. The system as claimed in claim 1, wherein the sensor is secured to the flange by means of screws.

4. The system as claimed in claim 1, wherein the sensor measures refractive index of the diesel exhausts fluid (DEF).

, Description:Field of invention

The present invention relates to quality measurement system and more particularly, the present invention relates to the system for measurement of diesel exhaust fluid (DEF) quality in a diesel engine vehicle.

Background of the invention

Diesel exhaust fluid (DEF) is an aqueous urea solution made with 32.5% urea and 67.5% deionized water. DEF is used as a consumable in selective catalytic reduction (SCR) in order to lower nitrogen oxide (NOx) concentration in the diesel exhaust emissions from diesel engines.

As per EPA guideline, poor quality of diesel exhaust fluid (DEF) has to be detected within 70 minutes of engine start. For refill conditions, non-compliance should be detected within one hour.

At temperatures above -8 Deg C, the DEF quality is getting detected in less than a minute since the DEF is in liquid state. However, at -11 Degrees and below, the DEF solution in the tank (1) freezes to ice which is a property of the DEF. The DEF tank includes a supply module (2) and a dosing module (3) as shown in figure 1. The supply module (2) includes an inbuilt heater is configured theein. The heater is supposed to de-freeze the frozen DEF. However, the heater is capable of heating the DEF only locally and not in the complete tank.

As the heating efficiency of the heaters configured in a tank is poor, the heaters do not melt the frozen DEF near to a DEF quality sensor (4). Specifically, the tank heaters takes more than 2 hours to melt the frozen DEF which results in delayed quality detection by the DEF quality sensor (4).

This duration of heating the tank (1) is way above and result in considerable delay. Accordingly, there exists a need to provide a system for (Diesel Exhaust Fluid) DEF quality measurement which overcomes above-mentioned drawbacks.

Objects of the present invention

An object of the present is to reduce the detection time of the quality of DEF.

Another object of the present invention is to reduce the addition of a heater in tank to defreeze the DEF.

Summary of the invention

Accordingly, the present invention provides a system for diesel exhaust fluid quality measurement. The system comprises a tank for holding diesel exhaust fluid therein, a supply module connected to the tank for supplying the diesel exhaust fluid to the tank, a flange welded to the tank and a sensor secured to the flange for measurement of the quality of diesel exhaust fluid. The system is characterized in that the sensor comprises heating element configured inside housing to heat the localized diesel exhaust fluid of the tank thereby providing immediate reading of the quality of the diesel exhaust fluid.

Typically, wherein the heating element is resistor.

Typically, wherein the sensor is secured to the flange by means of screws.

Brief description of the figures

The objectives and features of the present invention will be more clearly understood from the following description of the invention taken in conjunction with the accompanying drawings, wherein,

Figure 1 shows a block diagram of a system for (Diesel Exhaust Fluid) DEF quality measurement, in accordance with the prior art;

Figure 2 shows a block diagram of a system for (Diesel Exhaust Fluid) DEF quality measurement, in accordance with the present invention;

Figure 3A shows a cross sectional view of assembly of a sensor on a DEF tank;

Figure 3B shows an exploded view of assembly of the sensor; and

Figure 4 shows cross sectional view of the sensor of figure 3A.

Detailed description of the present invention:

The foregoing objects of the present invention are accomplished and the problems and shortcomings associated with the prior art, techniques and approaches are overcome by the present invention as described below in the preferred embodiment.

The present invention provides a system for measurement of quality of diesel exhaust fluid (DEF) measurement. The system provides for DEF quality measurement during sub zero conditions. The adaption of the system ensures no change in current system layout or design. Further, the heating logic of the system is independent of all other system constraints.

For the better understanding of this invention, reference would now be made to the embodiment illustrated in greater depth in the accompanying figures and description herein below, further, in the following figures, the same reference numerals are used to identify the same components in various views/figures.

Referring now to figure 2 to 4, there is shown a system (100) for diesel exhaust fluid (DEF) quality measurement, in accordance with the present invention. The system (100) comprises a tank (10), a supply module (20), a flange (30), a sensor (40), a heater element (50), a dosing module (60) and a heater control unit (70).

The tank (10) holds diesel exhaust fluid therein. The supply module (20) is connected the tank (10) to refill the tank (10) with the DEF in case poor quality of DEF fluid within the tank (10) is detected. The supply module (20) is connected to the dosing module (60).

The flange (30) is welded to the tank at one side as shown in figure 3A. The flange (30) comprises the sensor (40) secured thereto for measurement of the quality of diesel exhaust fluid. Specifically, the sensor (40) is secured in between the sealing ring (32) and holding plate (34) using a plurality of fastening screws (36) as shown in figure 3B.

The sensor (40) detects the quality of localized DEF fluid and sends signals to electronic control unit (ECU) of the vehicle. In an embodiment, the sensor (40) measures refractive index of the liquid urea of the DEF to determine the quality of the DEF.

Specifically, the sensor (40) is configured within the housing (42) which is secured to the flange (30). As shown in figure 4, the sensor (40) comprises a LED (44), light guide means (46) and a media chamber (48). The LED (44) measures the refractive index of the DEF in the media chamber (48) to detect the quality of the DEF. As the quality of the DEF deteriorates, the refractive index of the DEF is reduced.

The system (100) is characterized in that the sensor (40) comprises heating element (50) configured inside housing (42) to heat the localized DEF of the tank thereby providing immediate reading of the quality of the diesel exhaust fluid. In an embodiment, the heating element (50) is a resistor. The heating by the heating element of the localized DEF in the tank (10) give immediate reading to the ECU in less than 20 minutes.

The heating element (50) is controlled by the heating control unit (70). Using the heating control unit (70), temperature of the heating element (50) is maintained at required degrees as per surrounding atmospheric condition

Advantages of the invention

1. The system (100) is capable of measuring quality of the DEF during sub zero conditions.
2. The system (100) can be adopted universally as a part of heating strategy there is no change in original system layout or design.
3. The system (100) has heating logic independent of all other system constraints and over heat protection available.
4. The system (100) provides unique mounting of resistor inside housing of the sensor ensuring the localized heating the DEF.
5. The system (100) provides low cost solutions compared to independent heater inside the tank.
6. The system (100) provides immediate detection of the DEF quality inside the tank thus, ensuring no system level damages in vehicle.

The foregoing objects of the invention are accomplished and the problems and shortcomings associated with prior art techniques and approaches are overcome by the present invention described in the present embodiment. Detailed descriptions of the preferred embodiment are provided herein; however, it is to be understood that the present invention may be embodied in various forms. Therefore, specific details disclosed herein are not to be interpreted as limiting, but rather as a basis for the claims and as a representative basis for teaching one skilled in the art to employ the present invention in virtually any appropriately detailed system, structure, or matter. The embodiments of the invention as described above and the methods disclosed herein will suggest further modification and alterations to those skilled in the art. Such further modifications and alterations may be made without departing from the spirit and scope of the invention.