Sensor mounting module

Abstract

A sensor mounting module comprises: a sensor receiving portion configured, in use, to receive an exhaust gas sensor having a sensor body, one or more sensor inlets and one or more sensor outlets. The sensor is configured to sense a property of the gas flowing between the one or more sensor inlets and the one or more sensor outlets via a sensor passage. The sensor mounting module further comprises: a module inlet configured to direct gas towards the one or more sensor inlets; a module outlet; and an intermediate portion between the module inlet and the module outlet wherein the sensor mounting module is configured in use so as to receive the sensor body into the intermediate portion so as to restrict or prevent flow of gas through the intermediate portion other than via the sensor passage. The module inlet is configured to funnel the exhaust gas towards the one or more sensor inlets so as to increase pressure of the exhaust gas at the module inlet in order to provide a positive pressure differential between the module inlet and the module outlet.

Description

[0001] Sensor mounting module

[0002] Field of the disclosure

[0003] The disclosure relates to the field of exhaust gas sensors. In particular, this disclosure relates to a mounting module for an exhaust gas sensor.

[0004] Background

[0005] When burning fuel, such as diesel, petrol and / or alternative fuels such as hydrogen, internal combustion engines output various substances. In some circumstances, it may be desirable to process one or more of the output substances. This processing may assist in meeting current and future emissions legislation. Most commonly those substances comprise hydrocarbons (HC), carbon monoxides (CO), mono-nitrogen oxides (NOx) and particulate matter, such as carbon (C), a constituent of soot. The emission of some of those substances may be reduced by careful control of the operating conditions of the engine, but usually it is necessary to provide an engine after-treatment system downstream of the engine to treat at least some of those output substances.

[0006] For example, it is known to reduce or eliminate mono-nitrogen oxides (NOX) in diesel combustion emissions by conversion to diatomic nitrogen (N2) and water (H2O) by catalytic reaction with chemicals such as ammonia (NH3) entrained in the exhaust fluid. Generally, ammonia is not present in exhaust gases and must therefore be introduced upstream of a catalyst, typically by injecting an exhaust fluid, for example a reductant such as a urea solution, into the exhaust gas which decomposes into ammonia at sufficiently high temperatures. By this method, exhaust gases can be treated, meaning that a proportion of the substances which would otherwise be released to atmosphere are instead converted to nitrogen (N2) and water (H2O).

[0007] In order to effectively control the engine after-treatment system, it may be important to measure one or more properties of the exhaust gas flow, e.g. a temperature of the exhaust gas flow, a mass flow rate of the exhaust gas flow, and / or a quantity of a gas species (e.g. CO, or NOx) of the exhaust gas flow. For this purpose, one or more sensors may be

[0008] 15611444-18 provided along the exhaust gas flow. However, the accuracy and reliability of exhaust gas sensors can depend on factors such as positioning of the exhaust gas sensor within the exhaust gas flow, and limits of detection of the exhaust gas sensor. Moreover, providing a sensor along the exhaust gas flow can create flow disturbances which can affect the efficiency of the downstream engine after-treatment system. This can make it difficult to effectively control the engine after treatment system, and therefore can make it difficult to efficiently treat the substances output by the internal combustion engine. This in turn can make it difficult to make the internal combustion engine compliant with current or future emissions legislation.

[0009] Against this background, there is a need for improved ways of quantifying substances output by internal combustion engines.

[0010] Summary of the disclosure

[0011] Against this background, there is provided: a sensor mounting module comprising: a sensor receiving portion configured, in use, to receive an exhaust gas sensor having a sensor body, one or more sensor inlets and one or more sensor outlets, the sensor configured to sense a property of the gas flowing between the one or more sensor inlets and the one or more sensor outlets via a sensor passage; a module inlet configured to direct gas towards the one or more sensor inlets; a module outlet; an intermediate portion between the module inlet and the module outlet wherein the sensor mounting module is configured in use so as to receive the sensor body into the intermediate portion so as to restrict or prevent flow of gas through the intermediate portion other than via the sensor passage; wherein the module inlet is configured to funnel the exhaust gas towards the one or more sensor inlets so as to increase pressure of the exhaust gas at the module inlet in order to provide a positive pressure differential between the module inlet and the module outlet.

[0012] Due to the funnelling of the exhaust gas flow by the module inlet, and due to the restriction or prevention of the exhaust gas flow by the intermediate portion, the pressure of the exhaust gas within the module inlet increases. Thus, the positive pressure differential

[0013] 15611444-18 between the module inlet and the module outlet increases, which in turn may cause an increase in a velocity of the exhaust gas through the sensor passage when the sensor is in use with the sensor mounting module. Due to the increased velocity through the sensor passage, the accuracy of the exhaust gas sensor may be improved. Additionally, the increased velocity of the exhaust gas flow may be from below a limit of detection of the exhaust gas sensor to above a limit of detection of the exhaust gas sensor, increasing the reliability of measurements made by the exhaust gas sensor.

[0014] Brief description of the drawings

[0015] A specific embodiment of the disclosure will now be described, by way of example only, with reference to the accompanying drawings in which:

[0016] Figure 1 shows a sensing assembly comprising the sensor mounting module according to a first embodiment;

[0017] Figure 2 shows a first perspective view of the sensing assembly of Figure 1 ;

[0018] Figure 3 shows a module inlet of the sensor mounting module according to the first embodiment;

[0019] Figure 4 shows the module inlet of the sensor mounting module according to a second embodiment;

[0020] Figure 5 shows the module inlet of the sensor mounting module according a third embodiment;

[0021] Figure 6 shows a second perspective view of the sensing assembly of Figure 1 ;

[0022] Figure 7 shows the sensing assembly, comprising a fourth embodiment the sensor mounting module;

[0023] Figure 8 shows the sensing assembly, comprising a fifth embodiment of the sensor mounting module

[0024] Figure 9 shows the sensing assembly, comprising a sixth embodiment of the sensor mounting module;

[0025] Figure 10 shows a module outlet of the sensor mounting module according to a seventh embodiment;

[0026] Figure 11 shows the module outlet of the sensor mounting module according to an eighth embodiment;

[0027] Figure 12 shows an exhaust gas sensing system comprising sensor mounting module according to the first embodiment;

[0028] 15611444-18 Figure 13 shows the sensing assembly, comprising the sensor mounting module according to a ninth embodiment;

[0029] Figure 14 shows a flow simulation of a sensor without a sensor mounting module; Figure 15 shows a flow simulation of the sensing assembly comprising the sensor mounting module according to the first embodiment;

[0030] Figure 16 shows a table summarising flow velocities derived from flow simulations comparing the sensing assembly of Figure 14 with the sensing assembly of Figure 15;

[0031] Figure 17 shows a graph plotting the data of the table shown in Figure 16; and Figure 18 shows the sensing assembly, comprising the sensor mounting module according to a tenth embodiment.

[0032] Detailed description

[0033] According to one or more embodiments of this disclosure, a sensor mounting module 110 is provided.

[0034] Figure 1 shows a sensing assembly 100 comprising the sensor mounting module 110 according to the first embodiment. As shown in Figure 1 , the sensing assembly 100 further comprises an exhaust gas sensor 120. The exhaust gas sensor comprises one or more sensor inlets 122a, 122b, 122c and one or more sensor outlets 124. The exhaust gas sensor has a sensor body 152. The exhaust gas sensor 120 is configured to measure a property of an exhaust gas flow flowing between the one or more sensor inlets 122a, 122b, 122c and the one or more sensor outlets 124 via a sensor passage 151 . The exhaust gas flow may be through a conduit 140, for example an exhaust gas conduit of an engine after treatment system downstream of an internal combustion engine.

[0035] The measurement of the property of the exhaust gas flow by the exhaust gas sensor 120 may depend on a velocity of the exhaust gas flow. For example, an accuracy of the sensor (e.g. the accuracy of the exhaust gas sensor over a measurement time) may increase once the velocity of the exhaust gas flow through the sensor passage exceeds a threshold. The sensor mounting module 110 may be shaped to cause an increase in the velocity of the exhaust gas flow through the sensor passage 151 , thereby improving the accuracy of the exhaust gas sensor 120. A sensing element of the exhaust gas sensor 120 may be within the sensor passage 151 .

[0036] 15611444-18 As shown in Figure 1 , the sensor mounting module 110 is configured to receive the exhaust gas sensor 120 (Figure 1 shows the exhaust gas sensor received by the sensor mounting module 110). The sensor mounting module 110 comprises a sensor receiving portion configured 132, in use, to receive an exhaust gas sensor 120. For example, the sensor receiving portion 132may be shaped to fit around the exhaust gas sensor 120. The sensor mounting module 110 further comprises a module inlet 135 configured to direct the exhaust gas flow towards the one or more sensor inlets 122a, 122b, 122c. The sensor mounting module 110 further comprises a module outlet 137. The module outlet 137 may be configured to output the exhaust gas flow. As such, in use with the exhaust gas sensor 120, the exhaust gas flow may be received through the module inlet 135, directed via the exhaust gas sensor 120, and output from the module outlet 137. Due to the shape of the module inlet 135, a pressure of the exhaust gas flow increases within the module inlet 135 upstream of the exhaust gas sensor 120. The module inlet 135 defines an exhaust gas flow path (indicated generally by the dashed arrow labelled A). As shown in Figure 1 , the exhaust gas flow path A continues from the exhaust gas sensor 120 to the module outlet 137. As such, the exhaust gas flow path A may be from the module inlet 135 to the module outlet 137 via the exhaust gas sensor 120.

[0037] As shown in Figure 1 , the exhaust gas flow path A is from the module inlet 135 to the module outlet 137 via the exhaust gas sensor 120. The module inlet 135 is configured to funnel the exhaust gas towards the one or more sensor inlet 122a, 122b, 122c so as to increase pressure of the exhaust gas at the module inlet 135 in order to provide a positive pressure differential between the module inlet 135 and the module outlet 137. The exhaust gas sensor 120 may comprise a sensor mount 125. In use, as the exhaust gas flows through the exhaust gas sensor 120, the exhaust gas sensor 120 may measure the property of the exhaust gas flow. By receiving the sensor mount 125 within the mounting cavity 132, the module inlet 135 and the module outlet 137 may be located proximate the exhaust gas sensor 120. The module inlet 135 may have an inflow aperture 134 at an upstream end of the module inlet 135. Similarly, the module outlet 137 may have an outflow aperture 136 at a downstream end of the module outlet 137. Consequently, the exhaust gas flow path A from the module inlet 135 to the module outlet 137 may be via the exhaust gas sensor 120.

[0038] As shown in Figure 1 , the module inlet 135 may be aligned with a flow direction of exhaust gas (indicated by arrow B) within a conduit 140 in which the sensor mounting module 110

[0039] 15611444-18 may be installed. The sensor mounting module 110 may be configured to rotate and / or lock with respect to the sensor exhaust gas sensor 120 (the exhaust gas sensor 120 may in turn be mounted to the exhaust gas conduit 140 via the sensor mount 125). The exhaust gas may flow in the flow direction B through the exhaust gas conduit 140. By aligning the module inlet 135 with the flow direction B, the exhaust gas may flow through the module inlet 135 be directed towards the exhaust gas sensor 120. Due to the alignment of the module inlet 135 with the flow direction B, and the directing of the exhaust gas by the module inlet 135, the pressure of the exhaust gas flow within the module inlet 135 may increase.

[0040] The module inlet 135 may be shaped to narrow the exhaust gas flow path A upstream of the exhaust gas sensor 120. The module inlet 135 may be shaped to narrow the exhaust gas flow path from a first diameter at the inflow aperture 134 of the module inlet 135 to a second diameter proximate the exhaust gas sensor 120. The module inlet 135 may be shaped to narrow the exhaust gas flow path A linearly, and / or in a concave curve. As shown in Figure 1 , a first surface of the module inlet 135 may be shaped to narrow linearly, and a second surface may be shaped to narrow in a concave curve. The first surface may be opposite the second surface. In use, the first surface may be closer to the conduit 140 than the second surface. Since the upstream portion 135 is shaped to narrow the exhaust gas flow path A upstream of the exhaust gas sensor 12, in use the pressure of the exhaust gas increases in the module inlet 135.

[0041] The module inlet 135 may be configured to surround the exhaust gas sensor 120. The one or more sensor inlets 122a, 122b, 122c may comprise a plurality of sensor inlets122a, 122b, 122c.The exhaust gas sensor 120 may be configured to measure the property of the exhaust gas flow through the plurality of sensor inlets 122a, 122b, 122c. As shown in Figure 1 , the upstream portion 135 may surround the plurality of sensor inlets 122a, 122b, 122c. In use with the exhaust gas sensor 120, the exhaust gas flow path A is further defined by the sensor passage 151 of the exhaust gas sensor 120. The module inlet 135 may be shaped to surround the plurality of sensor inlets 122a, 122b, 122c such that the exhaust gas flow path A narrows between the upper portion 135 and the exhaust gas sensor 120 towards the plurality of sensor inlets 122a, 122b, 122c. In this way, the module inlet 135 directs the exhaust gas flow towards the plurality of sensor inlets 122a, 122b, 122c.

[0042] 15611444-18 The module inlet 135may surround the exhaust gas sensor 120 such that the module inlet 135 envelopes the exhaust gas sensor 120. For example, the exhaust gas sensor 120 may be coaxial with the sensor mounting module 110.

[0043] The plurality of sensor inlets 122a, 122b, 122c may comprise a first inlet 122a and a second inlet 122c. The second inlet 122c may be downstream of the first inlet 122a. For example, the second inlet 122c may be further from the inflow aperture 134 than the first inlet 122a. The first inlet 122a may be aligned more closely with the inflow aperture 134 than the second inlet 122c. The exhaust gas flow may be received by the inflow aperture 134, be directed by the module inlet 135 toward the first inlet 122a, at which point a first fraction of the exhaust gas flow may be received by the first inlet 122a, and a second fraction may be directed around the exhaust gas sensor 120 along the exhaust gas flow path toward the second inlet 122c (the exhaust gas flow path through the second inlet 122c is not shown in Figure 1). The second fraction of the exhaust gas flow may be received by the second inlet 122c. Since the module inlet 135 is shaped to surround the plurality of inlets 122a, 122b, 122c, the module inlet 135 redirects the exhaust gas flow toward the second inlet 122c. Additionally, the module inlet 135 may be shaped to narrow the exhaust gas flow path between the first inlet 122a and the second inlet 122c (the exhaust gas flow path between the first inlet 122a and the second inlet 122c is not shown in Figure 1). The narrowing of the exhaust gas flow path between the first inlet 122a and the second inlet 122c may cause the pressure of the exhaust gas flow to increase between the first inlet 122a and the second inlet 122c.

[0044] As shown in Figure 1 , in use, the module outlet 137 may be aligned in a direction transverse with the flow direction B. As such, the module outlet 137 may be aligned in a direction transverse with the module inlet 135. The module outlet 137 may extend from the exhaust gas sensor 120 in the direction transverse with the flow direction B. By extending the module outlet 137 transverse to the flow direction, the module outlet 137 may not receive a positive pressure from the exhaust gas flow. By comparison, since the module inlet 135 may in use be aligned with the flow direction B, the module inlet 135 may receive a positive pressure from the exhaust gas flow. In this way, the downstream portion 137 may cause a pressure to decrease downstream of the exhaust gas sensor 120. Due to the pressure decrease downstream of the exhaust gas sensor 120, the velocity of the exhaust gas flow along the sensor passage 151 of the exhaust gas sensor 120 may increase.

[0045] 15611444-18 The module outlet 137 may be shaped to expand the exhaust gas flow path A downstream of the exhaust gas sensor 120. For example, the exhaust gas sensor 120 may further comprise one or more sensor outlets 124. The exhaust gas sensor may be configured to output the exhaust gas flow through the one or more sensor outlets 124. Consequently, the exhaust gas flow path A may extend from the inflow aperture 134, through one of the plurality of sensor inlets 122a, 122b, or 122c, through one of the one or more sensor outlets 124, and through the outflow aperture 136 of the module outlet 137. Upstream of the one or more sensor outlets 124, the exhaust gas flow path A may be constrained to a third diameter by the exhaust gas sensor 120. Downstream of the one or more sensor outlets 124, the exhaust gas flow path A may expand to a fourth diameter towards the outflow aperture 136. Due to the expansion of the exhaust gas flow path A from the third diameter to the fourth diameter, the pressure of the exhaust gas flow may decrease downstream of the exhaust gas sensor 120. Due to the pressure decrease of the exhaust gas flow downstream of the exhaust gas sensor 120, the velocity of the exhaust gas flow within the exhaust gas sensor 120 (e.g. along the sensor passage 151) may increase.

[0046] As shown in Figure 1 , the sensor mounting module 110 further comprises an intermediate portion 138. The intermediate portion 138 may be between the module inlet 135 and the module outlet 137. The intermediate portion 138 is configured in use so as to receive a sensor body 152 of the exhaust gas sensor 120 into the intermediate portion 138 so as to restrict and / or prevent flow of gas through the intermediate portion 138 other than via the sensor passage 151.

[0047] The intermediate portion 138 may, in use with the exhaust gas sensor 120, contact the exhaust gas sensor 120.

[0048] The intermediate portion 138 may contact the exhaust gas sensor 120 between the plurality of sensor inlets 122a, 122b, 122c and the one or more sensor outlets 124. For example, the contacting portion 138 may contact the exhaust gas sensor 120 along a contact length. The contact length may be no less than 1 mm, no less than 1 cm, or no less than 5 cm. In this way, the exhaust gas flow may be prevented and / or restricted from bypassing the exhaust gas sensor 120. The contacting portion 138 may prevent and / or decrease the exhaust gas flow from bypassing the exhaust gas sensor 120 such that a majority of the exhaust gas flow is received by the plurality of sensor inlets 122a, 122b, 122c rather than bypassing the plurality of sensor inlets 122a, 122b, 122c.

[0049] 15611444-18 In some arrangements (not shown in the Figures), the intermediate portion 138 may be separated from the exhaust gas sensor 120 by a controlled gap (e.g. the controlled gap may be a gap of no more than 1 cm, or no more than 1 mm). The controlled gap may permit no more than 1%, no more than 5%, or no more than 10% of the exhaust gas flow to flow around the exhaust gas sensor 120 via the controlled gap.

[0050] Figure 2 shows a first perspective view of the sensing assembly 100 of Figure 1 . As shown in Figure 2, the inflow aperture 134 may be rectangular. In alternative arrangements (not shown in Figure 2), the inflow aperture 134 may be circular, a regular shape, or an irregular shape. The inflow aperture 134 may extend around no more than half, no more than a third, or no more than a quarter of the module inlet 135. In this way, the module inlet 135 may be aligned with the flow direction B (best seen in Figure 1 ) such that the module inlet 135 directs the exhaust gas flow towards the exhaust gas sensor 120. As can be seen in Figure 2, the exhaust gas flow path A surrounds the exhaust gas sensor 120.

[0051] The exhaust gas flow path A surrounding the exhaust gas sensor 120 is affected by how the module inlet 135 is shaped. Figures 3 to 5 show different embodiments of the sensor mounting module 110. The embodiments shown in Figures 3 to 5 differ in how the module inlet 135 is shaped.

[0052] Figure 3 shows the module inlet 135 of the sensor mounting module 1 10 according to the first embodiment. Figure 3 shows a cross section of the sensing assembly 100 of Figure 2, through the dashed line marked X in Figure 2. As shown in Figure 3, the module inlet 135 narrows from the inflow aperture 134 and then surrounds the exhaust gas sensor 120 in a partial circle 302. Consequently, the exhaust flow path 3A upstream of the sensor 120 follows a circular path 3A. Due to the circular path 3A, the exhaust gas flow is directed around the exhaust gas sensor 120 and towards the plurality of sensor inlets (an example inlet of the plurality of sensor inlets is marked 122a in Figure 3). The partial circle 302 may be no less than half, no less than two thirds, and / or no less than three quarters of a full circle. By surrounding the exhaust gas sensor 120 in the partial circle 302, the module inlet 135 distributes the exhaust gas flow evenly around the plurality of sensor inlets 122a.

[0053] Figure 4 shows the module inlet 135 of the sensor mounting module 1 10 according to a second embodiment. Figure 4 is similar to Figure 3, but Figure 4 does not show the

[0054] 15611444-18 exhaust gas sensor 120. Different to the first embodiment, the module inlet 135 of the second embodiment surrounds the exhaust gas sensor 120 in an inward spiral path 402. Consequently, the exhaust gas flow path A upstream of the sensor 120 follows an inward spiral path 4A. The inward spiral path 4A may narrow towards the plurality of sensor inlets 122a, 122b, 122c (not shown in Figure 4). A centre of the inward spiral path 4A may spiral inward about a centre of the sensor mounting module 110. The inward spiral path 4A may follow an Archimedean spiral, a hyperbolic spiral, a lituus spiral and / or a logarithmic spiral.

[0055] Figure 5 shows the module inlet 135 of the sensor mounting module 110 according a third embodiment. Figure 5 is similar to Figure 3, but Figure 5 does not show the exhaust gas sensor 120. Different to the first and second embodiments, the module inlet 135 of the third embodiment (shown in Figure 5) surrounds the exhaust gas sensor 120 in an eccentric path 5A. The eccentric path 5A may narrow towards the plurality of sensor inlets 122a, 122b, 122c (the plurality of sensor inlets 122a, 122b, 122c are not shown in Figure 5). The eccentric path 5A may follow an ellipse, a parabola, and / or a hyperbola. A focus of the eccentric path 5A may be aligned with a centre of the module outlet 137 and / or a centre of the exhaust gas sensor 120.

[0056] Figure 6 shows a second perspective view of the sensing assembly 100 of Figure 1 . As shown in Figure 6, the outflow aperture 136 may be circular. In alternative arrangements (not shown in Figure 6), the outflow aperture 136 may be rectangular, a regular shape, or an irregular shape. The exhaust gas flow path A surrounding the exhaust gas sensor 120 is affected by how the module outlet 137 is shaped. Figures 7 to 11 show the sensing assembly 100 each with different embodiments of sensor mounting module 110. The embodiments shown in Figures 7 to 11 differ in how the module outlet 137 is shaped.

[0057] As shown in Figure 6, the module outlet 137 may be shaped to expand the exhaust gas flow path A. For example, the module outlet 137 may be shaped to expand the exhaust gas flow path A towards the outflow aperture 136. The module outlet 137 may be shaped to expand the exhaust gas flow path A as a cone or as a dome.

[0058] Figure 7 shows the sensing assembly 100, comprising a fourth embodiment of the sensor mounting module 110. Figure 7 shows a cross section of the sensing assembly 100 of Figure 6, through the dashed line marked Y in Figure 6. In the fourth embodiment, the module outlet 137 is shaped to expand the exhaust gas flow path A as a dome.

[0059] 15611444-18 Figure 8 shows the sensing assembly 100, comprising a fifth embodiment of the sensor mounting module 110. Similar to Figure 7, Figure 8 shows a cross section of the sensing assembly 100 of Figure 6, through the dashed line marked Y in Figure 6. In the fifth embodiment, the module outlet 137 is different to the module outlet of the fourth embodiment. In the fifth embodiment, the module outlet 137 is shaped to expand the exhaust gas flow path linearly. For example, the module outlet 137 may be shaped to expand the exhaust gas flow path as a cone, or as a pyramid.

[0060] Figure 9 shows the sensing assembly 100, comprising a sixth embodiment of the sensor mounting module 110. Similar to Figures 7 and 8, Figure 9 shows a cross section of the sensing assembly 100 of Figure 6, through the dashed line marked Y in Figure 6. In the sixth embodiment, the module outlet 137 is different to the module outlet 137 of the fourth and fifth embodiments. In the sixth embodiment, the module outlet 137 is shaped to expand the exhaust gas flow path A as a cylinder. As such, the module outlet 137 may extend towards the outflow aperture 136 as a cylinder. In alterative arrangements (not shown in Figure 9), the module outlet may be shaped to expand the exhaust gas flow path A as a regular or irregular prism. As such, in the alternative arrangements, the module outlet 137 may extend towards the outflow aperture 136 as a regular or irregular prism.

[0061] Figure 10 shows the module outlet 137of the sensor mounting module 110 according to a seventh embodiment. Similar to Figure 7, Figure 10 shows a cross section of the sensing assembly 100 of Figure 6 through the line marked Y in Figure 6, but the view shown in Figure 10 only shows the sensor mounting module 110 below the line marked Z in Figure 6. The seventh embodiment is similar to the fourth embodiment in that the module outlet 137 may be shaped as a dome. Different to the fourth embodiment, the module outlet 137 of the seventh embodiment may be shaped to angle the module outlet 137 away from the flow direction B. For example, the module outlet 137 may be bevelled such that a first side 137a of the module outlet 137 extends further from the intermediate portion 138 and / or the one or more sensor outlets 124 than a second side 137b of the module outlet 137. In use, the first side 137a may be upstream of the second side 137b.

[0062] Figure 11 shows the module outlet 137 of the sensor mounting module 110 according to an eighth embodiment. Similar to Figure 8, Figure 11 shows a cross section of the sensing assembly 100 of Figure 6 through the line marked Y in Figure 6, but the view shown in

[0063] 15611444-18 Figure 11 only shows the module outlet 137 below the line marked Z in Figure 6. The eighth embodiment is similar to the fifth embodiment in that the module outlet 137 is shaped linearly (e.g. as a cone or as a pyramid). Different to the fifth embodiment, the module outlet 137 of the eighth embodiment may be shaped to angle the module outlet 137 away from the flow direction B. For example, the module outlet 137 may be bevelled such that a first side 137a of the module outlet 137 extends further from the intermediate portion 138 and / or the one or more sensor outlets 124 than a second side 137b of the module outlet 137. In use, the first side 137a may be upstream of the second side 137b.

[0064] Figure 12 shows a gas flow system 1200 comprising the sensing assembly 100, the sensing assembly 100 comprising the sensor mounting module 110 according to the first embodiment. As shown in Figure 12, the gas flow system 1200 may comprise the conduit 140 and one or more catalysts (a first catalyst 1202 and a second catalyst 1204 are shown in Figure 12). The sensing assembly 100 may be between the first catalyst 1202 and the second catalyst 1204. The sensing assembly 100 may be mounted to the conduit 140 such that sensing assembly 100 extends by a first distance into the exhaust gas flow through the conduit 140 such that the module inlet 135 is aligned with the flow direction B. The first distance may be no greater than 25%, no greater than 20%, no greater than 15%, no greater than 10% and / or no greater than 5% of a diameter of the conduit 140. Since the first distance may be a minority fraction of the diameter of the conduit 140, the sensing assembly 100 may not disturb the exhaust gas flow between the first catalyst 1202 and the second catalyst 1204. Consequently, turbulence across the second catalyst 1204 may be decreased, which may improve a catalytic performance of the second catalyst 1204.

[0065] The exhaust gas flow through the conduit 140 may be uniform or non-uniform. To account for non-uniformities of the exhaust gas flow, the sensor mounting module 110 may further comprise a plurality of flow sampling tubes 1302, 1304, 1306. Figure 13 shows the sensing assembly 100, comprising the sensor mounting module 110 according to a ninth embodiment. As shown in Figure 13, the sensing assembly 100 may comprise three flow sampling tubes 1302, 1304, 1306. Each of the flow sampling tubes 1302, 1304, 1306 may extend from the module inlet 135.

[0066] Each sampling tube 1302, 1304, 1306 may comprise a first end 1302a, 1304a, 1306a and a second end (not shown in Figure 13). Each of the second ends may be located at different locations within the conduit 140 to each of the other second ends. The plurality of

[0067] 15611444-18 flow sampling tubes 1302, 1304, 1306 may be configured to receive the exhaust gas flow through each of the second ends and output the exhaust gas flow the respective first end 1302a, 1304a, 1306a. Each of the sampling tubes may include a plurality of openings (not shown), for example perforated holes etc, configured to receive exhaust flow. Each of the first ends 1302a, 1304a, 1306a may output the exhaust gas flow to the module inlet 135, for example via a sampling tube receiver 1308 as shown in Figure 1 . The sampling tube receiver 1308 may be configured to receive each of the first ends 1302a, 1304a, 1306a. By receiving the exhaust gas flow from different locations, the property of the exhaust gas measured by the exhaust gas sensor 120 may be averaged across the different locations. In this way, the sensing assembly 100 may account for non-uniformities of the exhaust gas flow.

[0068] Figure 18 shows the sensing assembly 100, comprising the sensor mounting module according 110 to a tenth embodiment. Different to the sensor mounting module 110 according to the first to ninth embodiments, the sensor mounting module 110 according to the tenth embodiment is configured such that, in use with the exhaust gas sensor 120, the exhaust gas sensor 120 extends downstream of the module outlet 236. As such, the one or more sensor outlets 124 may be located downstream of the module outlet 236.

[0069] In any of the above embodiments, the exhaust gas sensor 120 may be configured to measure the property of the exhaust gas flow. The property of the exhaust gas flow measured by the exhaust gas sensor comprises one or more of: a quantity of a species of the exhaust gas flow; a temperature of the exhaust gas flow; a pressure of the exhaust gas flow; and a velocity of the exhaust gas flow. The quantity of the species of the exhaust gas flow may comprise one or more of a quantity of carbon monoxides (CO), mono-nitrogen oxides (NOx), oxygen (02), and / or ammonia (NH3).

[0070] The exhaust gas sensor may determine property of the exhaust gas in response to a flow through the exhaust gas sensor 120. As such, the property of the exhaust gas may be determined as the exhaust gas flows through the plurality of sensor inlets 122a, 122b, 122c. The property of the exhaust gas may be determined between the plurality of sensor inlets 122a, 122b, 122c and the one or more sensor outlets 124 along the sensor passage 151.

[0071] 15611444-18 Figure 14 shows a first flow simulation of a sensing assembly, not according to the claims. Figure 15 shows a second flow simulation of the sensing assembly 100 comprising the sensor mounting module 110 according to the first embodiment. Point Q1 in Figure 14 is between the plurality of sensor inlets 122a, 122b, 122c, and the one or more sensor outlets 124, and point Q3 in Figure 15 is at a comparable location to Q1 between the plurality of sensor inlets 122a, 122b, 122c, and the one or more sensor outlets 124.

[0072] At Q3, the velocity of the exhaust gas flow is higher than the velocity of the exhaust gas flow at Q1 . Therefore, the decrease in the pressure of the exhaust as flow downstream of the exhaust gas sensor 120 causes an increase in the velocity of the exhaust gas flow between the plurality of sensor inlets 122a, 122b, 122c, and the one or more sensor outlets 124 along the sensor passage 151 .

[0073] Figure 16 shows a table summarising flow velocities derived from flow simulations comparing the sensing assembly not according to the claims with the sensing assembly 100 comprising the sensor mounting module 110 of the first embodiment. In the second column (headed “Standard Mounting"), a velocity of the exhaust gas flow between the plurality of sensor inlets 122a, 122b, 122c, and the one or more sensor outlets 124, for the sensing assembly not according to the claims is shown. An example of the velocity in the second column may be the velocity at Q1 of Figure 14. In the third column (headed “Flow Amplifier"), a velocity of the exhaust gas flow between the plurality of sensor inlets 122a, 122b, 122c, and the one or more sensor outlets 124, for the sensing assembly 100 comprising the sensor mounting module 110 of the first embodiment is shown. An example of the velocity in the second column may be the velocity at Q3 of Figure 15. In the fourth column (“Amplification Factor”), a ratio between the third and second columns is shown.

[0074] As an example, the velocity of the exhaust gas flow between the plurality of sensor inlets 122a, 122b, 122c, and the one or more sensor outlets 124 was increased by an amplification factor of 5.9 by using the sensor mounting module 110 of the first embodiment for the third operating point “operating point 3”.

[0075] Figure 17 shows a graph of the data of the table shown in Figure 16. The x axis shows the operating point of the exhaust gas flow (as provided in the first column of the table shown in Figure 16). The operating points may each model with reference to a different external flow velocity. The y axis shows (on a logarithmic scale) the velocity of the exhaust gas flow

[0076] 15611444-18 between the plurality of sensor inlets 122a, 122b, 122c, and the one or more sensor outlets 124 (as provided in the second and third columns of Figure 16). The lower series corresponds with the sensing assembly not according to the claims (as provided in the second column of the table shown in Figure 16. The upper series corresponds with the sensing assembly 100 comprising the sensor mounting module 110 of the first embodiment (as provided in the third column of the table shown in Figure 16). As such, Figure 17 shows that the velocity of the exhaust gas flow between the plurality of sensor inlets 122a, 122b, 122c, and the one or more sensor outlets 124 is increased by using the sensing assembly 100 comprising the sensor mounting module 110 of the first embodiment compared with using the sensing assembly not according to the claims.

[0077] 15611444-18

Claims

CLAIMS:1 . A sensor mounting module comprising: a sensor receiving portion configured, in use, to receive an exhaust gas sensor having a sensor body, one or more sensor inlets and one or more sensor outlets, the sensor configured to sense a property of the gas flowing between the one or more sensor inlets and the one or more sensor outlets via a sensor passage; a module inlet configured to direct gas towards the one or more sensor inlets; a module outlet; an intermediate portion between the module inlet and the module outlet wherein the sensor mounting module is configured in use so as to receive the sensor body into the intermediate portion so as to restrict or prevent flow of gas through the intermediate portion other than via the sensor passage; wherein the module inlet is configured to funnel the exhaust gas towards the one or more sensor inlets so as to increase pressure of the exhaust gas at the module inlet in order to provide a positive pressure differential between the module inlet and the module outlet.

2. The sensor mounting module of claim 1 , wherein the module inlet is shaped to narrow an exhaust gas flow path upstream of the exhaust gas sensor such that a pressure of the exhaust gas flow increases upstream of the exhaust gas sensor.

3. The sensor mounting module of any preceding claim, wherein: the exhaust gas sensor is configured to measure the property of the exhaust gas flow through the one or more sensor inlets defined by the exhaust gas sensor, wherein: the module inlet surrounds the one or more sensor inlets and is configured to direct the exhaust gas flow towards the one or more sensor inlets.

4. The sensor mounting module of claim 3 as dependent on claim 2, wherein the one or more sensor inlets comprises a first inlet and a second inlet, and the module inlet is shaped such as to narrow the exhaust gas flow path between the first inlet and the second inlet, wherein the second inlet is downstream of the first inlet.15611444-185. The sensor mounting module of any preceding claim, wherein: the module outlet is configured to output the exhaust gas flow along an exhaust gas flow path downstream of the exhaust gas sensor.

6. The sensor mounting module of claim 5, wherein the module outlet is shaped to expand the exhaust gas flow path downstream of the exhaust gas sensor such that the pressure of the exhaust gas flow decreases downstream of the exhaust gas sensor.

7. The sensor mounting module of claim 6, wherein: the intermediate portion is configured in use to contact the exhaust gas sensor between the one or more sensor inlets and the more or more sensor outlets such as to prevent the exhaust gas flow from bypassing the exhaust gas flow sensor.

8. The sensor mounting module of claims 7, wherein: the module outlet is shaped such as to expand the exhaust gas flow path.

9. The sensor mounting module of any of claims 7 or 8, wherein the module outlet is shaped to expand the exhaust gas flow path as a cone, or as a dome.

10. The sensor mounting module of any of claims 7 to 9, wherein the module outlet extends as: a cylinder, a regular prism, or an irregular prism.11 . The sensor mounting module of any preceding claim, wherein the module inlet is shaped such that the exhaust gas flow path upstream of the sensor follows one or more of: an inward spiral path; a circular path; or an eccentric path.

12. The sensor mounting module of any preceding claim, further comprising a plurality of flow sampling tubes, wherein each of the flow sampling tubes extends from the module inlet.

13. A sensing assembly comprising: the sensor mounting module of any preceding claim; and an exhaust gas sensor configured to measure a property of an exhaust gas flow.15611444-1814. The sensing assembly of claim 13, wherein: the exhaust gas sensor is configured to measure the property of the exhaust gas flow through one or more of sensor inlets defined by the exhaust gas sensor.

15. The sensing assembly of claim 14, wherein the one or more sensor inlets are distributed circumferentially around the exhaust gas sensor.

16. The sensing assembly of any of claims 14 or 15, wherein: the exhaust gas sensor further comprises one or more sensor outlets, and the exhaust gas flows from the plurality of sensor inlets to the plurality of sensor outlets via the sensor passage.

17. The sensing assembly of claim 16, wherein: the exhaust gas sensor is configured to measure the property of the exhaust gas flow between the plurality of sensor inlets and the one or more sensor outlets along the sensor passage.

18. The sensing assembly of any of claims 14 to 17, wherein the property of the exhaust gas flow measured by the exhaust gas flow sensor comprises one or more of: a quantity of a species of the exhaust gas flow; a temperature of the exhaust gas flow; a pressure of the exhaust gas flow; and a velocity of the exhaust gas flow.

19. The sensing assembly of any of claims 15 to 20, wherein: the exhaust gas sensor is coaxial with the sensor mounting module.15611444-18

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