Module for supplying gas

Abstract

Aspects of the present invention relate to a module (2000) for supplying gas to a flame ionisation detector (3000). The module (2000) comprises a housing (200) configured to be mounted within a vehicle (5000). The housing (200) comprising a gas flow system (2010), the gas flow system comprising a gas bottle (220) for containing gas, wherein the gas bottle (220) is rigidly coupled within the housing (200) via one or more mounting arms (222) extending from an interior wall of the housing (200). The gas flow system (2010) further comprises a two-stage pressure regulator (236) coupled to the gas bottle (220). The gas flow system (2010) further comprises an output port (210) mounted through the housing (200) and coupled to the two-stage pressure regulator (236). The output port (210) is configured to supply gas to a flame ionisation detector (3000). The two-stage pressure regulator (236) and the output port (210) are coupled together by first piping (237). The gas bottle (220) and the two-stage pressure regulator (236) are coupled together by second piping (234), wherein the second piping (234) comprises a tortuous path. The housing (200) further comprises a first dampener configured to suppress oscillations of the gas bottle (220) and the two-stage pressure regulator (236).

Description

[0001] MODULE FOR SUPPLYING GAS

[0002] TECHNICAL FIELD

[0003] The present disclosure relates to a module for supplying gas to a flame ionisation detector. Aspects of the invention relate to a module, to a system, and to a vehicle.

[0004] BACKGROUND

[0005] It is known to test vehicle hydrocarbon emissions under laboratory conditions using a flame ionisation detector. Flame ionisation detectors use a hydrogen powered flame at a specific air-to-fuel ratio to measure total hydrocarbons through electrical generation via ionisation. However, new European vehicle emissions standards (EU7) require measurement of total hydrocarbons during an on-road test. Obtaining hydrocarbon emissions data onboard a vehicle travelling on real roads out of the laboratory presents a number of challenges in relation to data accuracy and repeatability. For example, vibrations experienced as a result of driving the vehicle on real, uneven, roads may lead to at oscillations in testing equipment, and, in severe cases could cause loosening of gas flow connectors leading to leaks. Additionally, ensuring the testing equipment is maintained at a relatively consistent temperature is important so that hydrocarbon emissions data obtained from vehicles operated in different climates can be reliably compared against common vehicle emissions standards.

[0006] It is an aim of the present invention to address one or more of the disadvantages associated with the prior art.

[0007] SUMMARY OF THE INVENTION Aspects and embodiments of the invention provide a module, a system, and a vehicle as claimed in the appended claims.

[0008] The invention provides a module for supplying gas to a flame ionisation detector on board a moving vehicle during on-road emissions testing.

[0009] According to an aspect of the present invention there is provided a module for supplying gas to a flame ionisation detector. The module comprises a housing configured to be mounted within a vehicle. The housing comprising a gas flow system, the gas flow system comprising a gas bottle for containing gas, wherein the gas bottle is rigidly coupled within the housing via one or more mounting arms extending from an interior wall of the housing. The gas flow system further comprises a two-stage pressure regulator coupled to the gas bottle. The gas flow system further comprises an output port mounted through the housing and coupled to the two-stage pressure regulator. The output port is configured to supply gas to a flame ionisation detector. The two-stage pressure regulator and the output port are coupled together by first piping. The gas bottle and the two-stage pressure regulator are coupled together by second piping, wherein the second piping comprises a tortuous path. The housing further comprises a first dampener configured to suppress oscillations of the gas bottle and the two-stage pressure regulator.

[0010] The claimed invention addresses data accuracy challenges associated with performing hydrocarbon emissions testing on board a vehicle during test drives. The claimed module contains a number of features that ensure a required gas flow is provided to a flame ionisation detector in a reliable manner. For example, the gas bottle is rigidly coupled to the module housing away from a wall of the housing to mitigate against impact events that could lead to gas pressure fluctuations. Additionally, a two-stage pressure regulator is provided to mitigate against pressure fluctuations leaving the gas bottle (particularly as the contents of the gas bottle diminish). The use of pipework comprising a plurality of bent portions ensures that pressure fluctuations leaving the gas bottle substantially peter out before reaching the two-stage regulator. Moreover, a dampener is provided to the housing that suppress oscillations of the gas bottle and two-stage pressure regulator, thus ensuring gas pressure fluctuations are minimised. The claimed invention therefore ensures that a required gas flow is reliably provided to a flame ionisation detector, such that hydrocarbon emissions testing having a high degree of accuracy can be performed on board the vehicle.

[0011] Optionally, the first dampener is disposed on the one or more mounting arms. In this way, vibration of the gas bottle is suppressed, thereby improving the stability of the gas flow leaving the gas bottle. Optionally, the first dampener is provided between the two-stage pressure regulator and an internal wall of the housing. In this way, vibration of the two-stage pressure regulator is suppressed (e g., as a result of vehicle motion on uneven terrain that could cause pressure needle jumps), thus providing reliable gas pressure control.

[0012] Optionally, the module comprises a gas detector mounted within the housing, the gas detector may be configured to detect a gas concentration in the housing. For example, the gas detector may be configured to detect a gas concentration within the internal volume of the housing that can be compared against a gas concentration threshold, In this way, gas leaks within the housing can be detected which may, for example, have caused gas pressure fluctuations between the two-stage pressure regulator and the output port, leading to unreliable gas flow to the flame ionisation detector.

[0013] Optionally, the housing further comprises a second dampener provided between the gas detector and an internal wall of the housing. In this way, vibration of the gas detector is suppressed, thus protecting internal components of the gas detector, resulting in reliable gas concentration readings.

[0014] Optionally, the first dampener comprises one or both of a rubber material and a spring. Optionally, the second dampener comprises one or both of a rubber material and a spring.

[0015] Optionally, the two-stage pressure regulator comprises a membrane comprising a plurality of pores, each pore having a pore size such that passage of gas contaminants through the two-stage pressure regulator is substantially prevented. In this way, gas having the required purity is provided to the flame ionisation detector, thus avoiding the risk of gas contaminants reaching the flame ionisation detector that could change flame stability of the flame ionisation detector.

[0016] Optionally, the first piping comprises a tortuous path. In this way, fluctuations in gas pressure occurring between the two-stage regulator and the output port peter out before reaching the output, thereby ensuring that a stable gas flow is delivered to the flame ionisation detector.

[0017] Optionally, the output port and the two-stage pressure regulator each comprise first threaded connectors. The first piping may be coupled to the output port and the two-stage pressure regulator via the first threaded connectors. Optionally, the gas bottle and the two-stage pressure regulator each comprise second threaded connectors. The second piping may be coupled to the gas bottle and the two-stage pressure regulator via the second threaded connectors. By using threaded connectors (as opposed to, for example, push-fit connectors), a robust connection is provided between components of the module. As such, consistent gas supply pressure integrity is ensured, for example during harsh emission testing conditions on uneven terrain.

[0018] Optionally, the module comprises one or more alignment marker pairs configured to indicate a required mechanical connection tightness between one or both of the first threaded connectors and the first piping; and the second threaded connectors and the second piping. In this way, a person monitoring the system is provided with an early indication of pipe-connector loosening is provided that could affect gas supply pressure integrity.

[0019] Optionally, the first piping, the second piping, the first threaded connectors and the second threaded connectors are formed from 316L austenitic grade stainless steel. In this way, contamination of the gas flow, and pressure drops capable of compromising flame stability, are mitigated.

[0020] Optionally, an inner diameter of the first piping and the second piping is sized so as to provide a substantially laminar flow of gas therethrough. In this way, a stable gas supply pressure is provided to the flame ionisation detector to ensure accurate hydrocarbon quantification.

[0021] Optionally, the housing comprises a plurality of walls each formed from a metallic layer sandwiched between a first non-metallic layer and a second non-metallic layers, wherein a thickness of the metallic layer is less than a thickness of the first non-metallic layer and a thickness of the second non- metallic layer. In this way, the overall weight of the module can be reduced whilst preventing gas permeation into / out of the module via the housing walls.

[0022] Optionally, the metallic layer is aluminium, and the first and second non-metallic layers are carbon fibre. Optionally, the gas bottle is mounted horizontally with respect to a chassis of the vehicle. Horizontal mounting of the gas bottle allows for the bottle to be placed lower in the module housing, thereby keeping the centre of gravity lower and improving the stability of the module.

[0023] According to another aspect of the invention, there is provided a system. The system comprises a flame ionisation detector, a first module according to the module mentioned above, and a second module according to the module mentioned above.

[0024] Optionally, a combined length of the first piping and the second piping of the first module is equal to a combined length of the first piping and the second piping of the second module. In this way, temperature effects on the gas supply within the first module and within the second module are equalised.

[0025] Optionally, the system further comprises first external piping coupled between the first module and the flame ionisation detector. Optionally, the system further comprises second external piping coupled between the second module and the flame ionisation detector, wherein the first external piping and the second external piping have a common length. In this way, temperature effects on the gas supply from the first module and from the second module are equalised.

[0026] Optionally, the first external piping and the second external piping have a common inner diameter. In this way, pressure differences between the first external piping and the second external piping are mitigated, ensuring that a consistent gas pressure is supplied to the flame ionisation detector from both the first and second modules.

[0027] Optionally, the output port of the first module has a different configuration to the output port of the second module. For example, the output ports of the first and second modules may have different shapes and / or different diameters. In this way, the risk of incorrect output port connections between the first and second module is mitigated.

[0028] According to a further aspect of the invention, there is provided a vehicle comprising the module as mentioned above, or the system as mentioned above.

[0029] Within the scope of this application it is expressly intended that the various aspects, embodiments, examples and alternatives set out in the preceding paragraphs, in the claims and / or in the following description and drawings, and in particular the individual features thereof, may be taken independently or in any combination. That is, all embodiments and / or features of any embodiment can be combined in any way and / or combination, unless such features are incompatible. The applicant reserves the right to change any originally filed claim or file any new claim accordingly, including the right to amend any originally filed claim to depend from and / or incorporate any feature of any other claim although not originally claimed in that manner.

[0030] BRIEF DESCRIPTION OF THE DRAWINGS

[0031] One or more embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

[0032] Figures 1 A and 1 B show perspective views of a module for supplying hydrogen gas to a flame ionisation detector according to an embodiment of the present invention;

[0033] Figure 2 shows a side view of the module for supplying hydrogen gas according to an embodiment of the invention;

[0034] Figure 3 shows a cross-sectional view of the module for supplying hydrogen gas as viewed from above the module, according to an embodiment of the present invention;

[0035] Figure 4 shows a cross-sectional view of the module for supplying hydrogen gas as viewed from an end of the module, according to an embodiment of the present invention; Figure 5 shows a cross-sectional view of the module for supplying hydrogen gas as viewed from an end of the module, according to an embodiment of the present invention; Figure 6 shows a schematic illustration of vehicle in accordance with an embodiment of the invention;

[0036] Figures 7A and 7B show perspective views of a module for supplying air gas to a flame ionisation detector according to an embodiment of the invention; Figure 8 shows a side view of the module for supplying air gas according to an embodiment of the invention;

[0037] Figure 9 shows a cross-sectional view of the module for supplying air gas as viewed from above the module, according to an embodiment of the present invention; Figure 10 shows a cross-sectional view of the module for supplying air gas as viewed from an end of the module, according to an embodiment of the present invention; and

[0038] Figure 11 shows a schematic illustration of a rear-view of the vehicle of Figure 6. DETAILED DESCRIPTION

[0039] The present disclosure provides a module for supplying hydrogen gas, a module for supplying air gas, and a modular system comprising the module for supplying hydrogen gas, the module for supplying air gas, and a flame ionisation detector.

[0040] Module for Supplying Hydrogen Gas

[0041] With reference to Figures 1 A and 1 B, there is illustrated a module 1000 for supplying hydrogen gas to a flame ionisation detector (not shown).

[0042] As mentioned above, new European vehicle emissions standards (EU7) require measurement of total hydrocarbons during an on-road test. However, this requirement leads to a number of challenges with performing such hydrocarbon emission measurements using flame ionisation detectors on board a moving vehicle, such as the potential for hydrogen gas to accumulate within the vehicle as a result of leakages in the supply of hydrogen gas to the flame ionisation detector during the on-road emissions testing. It is not practical or suitable to mount the module for supplying hydrogen gas 1000 (hereinafter referred to as “the hydrogen module 1000”) external to the vehicle, most notably due to the risk of impact events which could lead toa thermal event. Furthermore, if the hydrogen module 1000 is exposed to ambient temperatures outside of the vehicle, resulting temperature fluctuations in hydrogen gas supplied by the hydrogen module 1000 could lead to inaccurate hydrocarbon emission measurements. To overcome these issues, the housing 100 ofthe hydrogen module 1000 is configured to be mounted within a vehicle. One practical solution (shown in more detail by Figure 11) is to mount the hydrogen module 1000 within a boot space of the vehicle 5000.

[0043] As shown by Figure 1 B, the housing 100 has a lid 102 connected to the housing 100 by one or more hinges 106. The lid 102 may be fastened against the housing 100 by one or more clasps 104, as shown in Figure 1A, in order to form a lockable, gas-tight, enclosure. The housing 100 may also comprise one or more handles 108 affixed to opposing sides of the housing to facilitate transportation of the hydrogen module 1000 into / out of the vehicle 5000.

[0044] The housing 100 comprises an output port 110 mounted through the housing 100, the output port being configured to selectively couple the hydrogen module 1000 to a flame ionisation detector such that hydrogen gas can delivered from inside the hydrogen module 1000 to the flame ionisation detector. The output port 110 may be mounted in a location through the housing such that the risk of failure of the output port 110 due to mechanical shock (e.g . , in the event of a vehicle impact) is low. The output port 110 may comprise a connector configured to removably couple to a conduit (such as a hose or some other suitable piping) to allow the hydrogen gas to flow from the hydrogen module 1000 to the flame ionisation detector. The output port 110 may be designed so as to avoid natural hydrogen accumulation points within the output port 110.

[0045] The housing 100 and lid 102 of the hydrogen module 1000 may be formed from a material that is compatible for use with hydrogen gas in order to limit hydrogen diffusion out of the hydrogen module in the event of a hydrogen gas leak within the housing 100. For example, the housing 100 and lid 102 are formed from a material that is resistant to becoming brittle from exposure to hydrogen gas (that could result in hydrogen gas seepage out of the hydrogen module 1000). The material of the housing 100 and lid 102 form an enclosure that is certified to be fire-rated for at least one hour. The housing 100 and lid 102 may be constructed from, for example, stainless steel (e g., 316L austenitic grade), or composite material such as carbon fibre reinforced plastic. The skilled person would appreciate that other materials may be suitable, such as a low-nickel aluminium alloy, a copper alloy, or some ferritic steels (with appropriate thicknesses depending on worst-case mechanical impact tolerances).

[0046] The housing 100 may comprise a manual actuation value 112 mounted through the housing 100. The manual actuation valve 112 may be configured to permit the flow of hydrogen gas out from the hydrogen module 1000 via the output port 110, and configured such that the manual actuation value 112 is only operable when the hydrogen module is coupled to the flame ionisation detector. The manual actuation valve 112 and the output port 110 may be dimensioned so as to provide a substantially laminar flow of hydrogen gas therethrough, such that local accumulation of hydrogen gas and risk of pressure drops is reduced. Additionally, the provision of a stable laminar flow of hydrogen gas to the flame ionisation detector helps to ensure robust hydrocarbon emission data quality. The manual actuation valve may also have oversized physical dimensions in order to mitigate the risk of local pressure drops and hydrogen gas accumulation.

[0047] The housing 100 may comprise a gas duct (or extract) 114 mounted through the housing 100. The gas duct 114 is configured to be mechanically coupled to the vehicle exterior, (e.g . , via a conduit such as a hose) such that, in the event of a hydrogen gas leak within the housing 100, the hydrogen gas can be vented out of the housing 100 via the gas duct 114 and to the vehicle exterior. The gas duct 114 may have oversized physical dimensions to ensure that pressurisation of the housing 100 does not occur in the event of a gas bottle 120 containment failure. The housing 100 may be designed such that the gas duct 114 is located at a natural hydrogen accumulation point within the housing 100 to maximise the efficiency of hydrogen gas extraction from the housing 100 in the event of a hydrogen gas leak. For example, as shown by Figure 1A, the gas duct 114 may be located on a top surface of the housing 100, and optionally, proximate to any components where leakage could occur (e.g., where there are multiple connection points). As shown by Figure 1 B, the housing 100 may also comprise a vent 118 disposed through a wall of the housing 100, the vent 118 being configured to allow ambient air to enter the housing 100 in the event of a hydrogen leak within the housing 100, such that leaked hydrogen is purged from the housing 100 via the gas duct 114. The vent 118 may have one or more fans (such as brushless fans) to help draw ambient air into the housing 100.

[0048] A pressure relief outlet 116 may be disposed through a side wall of the housing 100, as shown by Figure 1A. The pressure relief outlet 116 may be connected to a gas flow system located within the housing 100 (discussed in more detail below with respect to Figures 3 to 5) and configured to allow hydrogen gas to safely escape from a pressure regulator within the housing 100 in the event that hydrogen gas pressure within the pressure regulator reaches a pressure threshold.

[0049] Figure 2 illustrates a side view of housing 100 of hydrogen module 1000, and shows view lines A-A, B-B and C-C which will be used in subsequent figures to illustrate various internal views of housing 100.

[0050] Figure 3 shows a cross-sectional view of the housing 100 of hydrogen module 1000 as viewed along line A-A of Figure 2. Figure 3 shows the features that would be visible inside the hydrogen module 1000 by opening the lid 102 of the hydrogen module 1000 and looking down into the hydrogen module 1000. The housing 100 comprises a gas flow system 1010. The gas flow system 1010 comprises a gas bottle 120 that contains a gas at least comprising hydrogen to be supplied, via the output port 110, to a flame ionisation detector. Optionally, the gas is a hydrogen / helium mix gas, wherein the mix ratio may be 60% hydrogen and 40% helium. The lid 102 of the housing 100 may be interlocked such that hydrogen gas will not flow from the gas bottle 120 if the lid 102 is open. The gas bottle 120 is coupled to the housing 100. For example, one or more mounting arms 122 may extend from an interior wall of the housing 100 to form a cradle onto which the gas bottle 120 is mounted. Whilst Figure 3 shows a pair of mounting arms 122 for mounting the gas bottle 120, the skilled person would appreciate that a single mounting arm could be provided to support the gas bottle 120. For example, a single mounting arm having a width spanning substantially the width of the gas bottle 120 may be provided instead of the pair of mounting arms 122 shown in Figure 3. Similarly, the skilled person would appreciate that three or more mounting arms may instead be provided to support the gas bottle 120. By extending from an interior wall of the housing 100, the one or more mounting arms 122 provide a region of empty space between the interior wall of the housing 100 and the gas bottle 120. This region of empty space leads to the formation of a crumple zone around the gas bottle 120 such that, in the event of a vehicle impact, the risk of damage to the gas bottle 120 is minimised. One or more straps 124 (or other suitable means for securing the gas bottle 120) may be attached to the mounting arms 122 and pass around the circumference of the gas bottle 120 to rigidly couple the gas bottle 120 within the housing 100. The gas bottle 120 may have a 1 litre capacity and be compressed to a pressure of 200 Bar gauge. It will however be appreciated that the gas bottle 120 may be any suitable size, for example, depending on the size of the housing 100 and / or amount of gas needed for the emissions test.

[0051] As shown by Figure 3, the gas bottle 120 may be mounted horizontally within the housing 100 (e.g., relative to the base of the housing 100 and with respect to a chassis of the vehicle in which housing 100 is placed) . By mounting the gas bottle 120 horizontally, the gas bottle 120 can be positioned relatively lower within the housing 100 (see, for example, Figures 4 and 5), thereby improving the stability of the hydrogen module 1000 because a centre of gravity of the housing 100 is lowered. The gas bottle 120 may comprise a high-pressure gas value 128 for controlling the flow of hydrogen gas out of the gas bottle 120. Dampening material may be provided between the gas bottle 120 and the housing 100 (e.g., on the one or more mounting arms 122) in order to suppress oscillation of the gas bottle 120 (e.g., as a result of the vehicle being driven on an uneven road surface during hydrocarbon emission testing). The dampening material may also mitigate the risk of damage to the gas bottle 120 in the event of impact. The dampening material may comprise one or more springs, and / or a rubber material.

[0052] The gas flow system 1010 further comprises a pressure regulator 136 coupled between the gas bottle 120 and the output port 110 via piping. The pressure regulator is configured to control a pressure of the hydrogen gas received from the gas bottle 120 , such that a required pressure of hydrogen gas (as dictated by the requirements of the flame ionisation detector) is provided to the output port 110. The pressure regulator 136 may comprise dials 138a, 138b to provide a visual indication of the hydrogen gas pressure to an operator of the hydrogen module 1000. For example, dial 138a may indicate an inlet pressure received from the gas bottle 120 at an inlet of the pressure regulator 136, and dial 138b may indicate an outlet pressure leaving an outlet of the pressure regulator 136 to the output port 110. The pressure regulator 136 may be a single stage pressure regulator. Alternatively, the pressure regulator 136 may be a two-stage pressure regulator, such that the pressure of the hydrogen gas received from the gas bottle 120 is reduced progressively in two steps instead of one, thereby delivering a more constant hydrogen gas pressure to the outport 110 than would be achievable with a single stage pressure regulator, and mitigating hydrogen gas pressure fluctuations from the gas bottle 120. Dampening material may be provided between the pressure regulator 136 and the housing 100 in order to suppress oscillation of the pressure regulator 136 (e.g. , as a result of the vehicle being driven on an uneven road surface during hydrocarbon emission testing). The dampening material may comprise one or more springs, and / or a rubber material. The pressure regulator 136 may comprise a membrane having a plurality of pores. Each pore may have a pore size such that passage of gas contaminants through the pressure regulator 136 is substantially prevented, in order to maintain a required purity of the hydrogen gas being supplied to the flame ionisation detector.

[0053] A gas safety device 132 may be coupled between the gas bottle 120 and the pressure regulator 136. For example, the gas safety device 132 may be coupled to an outlet of the gas bottle 120 at a neck portion 126 of the gas bottle 120. The gas safety device 132 may be configured to prevent back-flow of exothermic energy towards the gas bottle 120, such that any sparks or flash in exothermic energy travelling back through the gas flow system 1010 towards the gas bottle 120 will be stopped before reaching the gas bottle 120, thereby reducing the risk of explosive events. In one example, the gas safety device 132 may be a flashback arrestor. The gas safety device 132 is constructed from a material that is compatible with hydrogen gas. The gas safety device 132 and the pressure regulator 136 may be coupled together via piping 134 comprising a tortuous path therebetween. For example, the piping 134 (sometimes referred to as “pigtail piping”) may comprise a plurality of bent portions between the gas safety device and the pressure regulator 136 such that pressure fluctuations in the hydrogen gas leaving the gas bottle 120 peter out before reaching the pressure regulator 136. In general, the piping within the housing 100 (including pipework 134) comprises a material suitable for use with hydrogen gas, such that diffusion of hydrogen gas into the housing is prevented. For example, the piping within the housing 100 may be stainless steel (e.g., 316L austenitic grade). The piping within the housing 100 is typically coupled to respective components within the housing by connectors. In Figure 3, the piping 134 is connected to the pressure regulator 136 via a nut 135. The pressure regulator 136 may have a threaded connector onto which a corresponding threaded nut 135 is tightened to provide a gas-tight seal between piping 134 and the pressure regulator 136. As with the piping 134, nut 135 may also be made from stainless steel (e.g., 316L austenitic grade). Whilst it will be appreciated any fastener suitable for providing a gas-tight seal may be used, the use of threaded connections (compared to, for example, push-fit connections) between the components of the hydrogen module 1000 and corresponding piping is particularly advantageous in that it ensures a mechanically tight coupling which is resistant to loosening due to vibrations caused by motion of the vehicle. The hydrogen module 1000 may also comprise one or more alignment-marker pairs between a given nut and piping connected thereto. For example, piping 134 may have a visual and / or tactile marker, and nut 135 may have a corresponding visual and / or tactile marker, which, when aligned, indicate a required mechanical connection tightness between the piping 134 and the nut 135. As such, when installing or inspecting the gas flow system 1010, an operator can ensure that all components of the gas flow system 1010 are suitably connected together with appropriate mechanical tightness so that hydrogen gas leaks are mitigated. The skilled person would appreciate that any length of piping and corresponding nut within the housing 100 may be provided with corresponding alignment-marker pairs. The rigid anchoring of the gas bottle 120 to the one or more mounting arms 122 helps to avoid the transfer of force from vehicle impact events to threaded connections within the housing 100.

[0054] A first solenoid valve 130 may be coupled between the gas bottle 120 and the pressure regulator 136. More specifically, the first solenoid valve 130 may be coupled between the gas safety device 132 and the inlet of the pressure regulator 136 via piping 134. Figure 4 illustrates a cross-sectional view through the housing 100 of hydrogen module 1000 as viewed along line C-C of Figure 2, showing in more detail the relative placement of the gas bottle 120, first solenoid valve 130 and pipework 134 within the housing 100. In an open state, the first solenoid valve 130 permits the flow of hydrogen gas from the gas bottle 120 to the pressure regulator 136, and in a closed state, the first solenoid valve 130 prevents the flow of hydrogen gas from the gas bottle 120 to the pressure regulator 136. The first solenoid valve 130 may be an ATEX rated solenoid valve.

[0055] A second solenoid valve 140 may be coupled between the gas bottle 120 and the output port 110. More specifically, the second solenoid valve 140 may be coupled between the outlet of the pressure regulator 136 and hydrogen gas supply piping 144 that is coupled to the output port 110. In an open state, the second solenoid valve 140 permits the flow of hydrogen gas towards the output port 110, and in a closed state, the second solenoid valve 140 prevents the flow of hydrogen gas towards the output port 110. Figure 5 illustrates a cross-sectional view through the housing 100 of hydrogen module 1000 as viewed along line B-B of Figure 2, showing in more detail the relative placement of the gas bottle 120, second solenoid valve 140, hydrogen gas supply piping 144 and output port 110 within the housing 100. As shown by Figure 5, the hydrogen gas supply piping 144 is coupled to the output port 110 via the manual actuation valve 112. A one-way valve 148 is coupled between the manual actuation valve 112 and the second solenoid 140 in order to prevent back-flow of hydrogen gas through the pressure regulator 136 via hydrogen gas supply piping 144, which could damage the pressure regulator 136.

[0056] As the second solenoid valve 140 is located on the outlet-side of the pressure regulator 136, the second solenoid valve 140 is configured to operate at lower gas pressures than the first solenoid value 130 (which is located on the inlet-side of the pressure regulator 136 and is therefore exposed to relatively higher gas pressures received from the gas bottle 120). Like the first solenoid valve 130, the second solenoid valve 140 may be an ATEX rated solenoid valve.

[0057] Returning to Figure 3, the pressure regulator 136 may be coupled to pressure relief piping 142. The pressure relief piping 142 may be coupled to the pressure relief outlet 116 shown in Figure 1 A, and allow hydrogen gas to be exhausted out of the hydrogen module 1000 in the event of failure of the pressure regulator 136 (e.g., if a diaphragm of the pressure regulator 136 fails). The provision of the pressure relief piping 142 and outlet 116, together with active venting of the housing 100 via the gas duct 114 and vent 118 ensure that a gas pressure within the housing 100 does not exceed 2 Bar gauge.

[0058] The hydrogen module 1000 may comprise a control system 1020. The control system 1020 may include a programmable logic control system configured to isolate the supply of hydrogen gas within housing 100. The control system 1020 may include a relay system 145 having one or more relays in communication with the first solenoid valve 130 and the second solenoid valve 140. The programmable logic control system may be communicably coupled to one or more gas detector modules 146a, 146b located within the housing 100. The one or more gas detector modules 146a, 146b are configured to detect a concentration of hydrogen gas within the housing 100, and may be positioned within the housing 100 at a hydrogen gas accumulation point within the housing 100 so that the one or more gas detector modules 146a, 146b detect hydrogen as it rises within the housing 100. For example, the one or more gas detector modules 146a, 146b may be positioned away from a floor of the housing 100, and may be positioned substantially above the outlet of the gas bottle 120. Upon detection by the one or more gas detector modules 146a, 146b of a hydrogen gas concentration within the housing 100 meeting a hydrogen gas concentration threshold (indicative of a leak), the programmable logic control system activates the one or more relays 145 to close the first solenoid valve 130 and the second solenoid valve 140 so that hydrogen gas is prevented from flowing through the gas flow system 1010 and out of the housing 100 via output port 110. The hydrogen gas concentration threshold may be set well below the lower explosive limit of hydrogen on air of 4%. For example, the hydrogen gas threshold may be set at 10 parts per million (ppm). As such, the hydrogen gas concentration threshold is set such that the programmable logic control system activates the one or more relays 145 to close the first solenoid valve 130 and the second solenoid valve 140 well before the hydrogen concentration levels within the housing 100 reaches an unacceptable level. The housing 100 may have one or more removable panels to facilitate inspection and maintenance of the one or more gas detector modules 146a, 146b.

[0059] Dampening material may be provided between the one or more gas detector modules 146a, 146b and the housing 100 in order to suppress oscillation of the one or more gas detector modules 146a, 146b (e.g., as a result of the vehicle being driven on an uneven road surface during hydrocarbon emission testing), and thereby maintain the accuracy of readings provided by the one or more gas detector modules 146a, 146b. The dampening material may comprise one or more springs, and / or a rubber material. In addition to dampening material, the pressure regulator 136 may be mounted away from walls of the housing 100 to reduce oscillations of the pressure regulator 136.

[0060] In Figure 3, a first gas detector module 146a configured to detect a first hydrogen gas concentration within the housing 100, and a second gas detector module 146b configured to detect a second hydrogen gas concentration within the housing 100 are provided. The presence of two gas detector modules provides redundancy in the event that one of the gas detector modules 146a, 146b fails. The programmable logic control system may also determine whether the first hydrogen gas concentration and the second gas concentration agree within an agreement threshold and isolate the supply of hydrogen gas by closing the first and second solenoid valves 130, 140 upon determining that the first hydrogen gas concentration and the second gas concentration do not agree within the agreement threshold (for example, if one of the gas detector modules indicates a hydrogen gas leak but the other does not).

[0061] The programmable logic control system may be communicably coupled to the gas duct 114 shown by Figure 1A. Once a hydrogen leak within the housing 100 has been detected, and the first solenoid valve 130 and the second solenoid value 140 have been closed to prevent hydrogen gas flowing through the gas flow system 1010 and out of the housing via the output port, hydrogen gas can escape from the housing 100 via the gas duct 114, which is always in an open state to allow hydrogen gas to be safely extracted from the housing 100 and out of the vehicle, for example via a hose connected to the gas duct 114 (see Figure 11). During motion of the vehicle, hydrogen gas may be extracted from the housing 100 via the gas duct 114 and out of the vehicle by the Venturi effect. In order to compensate for leaks occurring when the vehicle speed is low or the vehicle is stationary, hydrogen gas may be actively expelled from the housing 100 and out of the vehicle via one or the more fans located along a base of the housing 100, which are configured to rotate to draw ambient air into the housing 100 via vent 118 so that hydrogen gas is purged out of the housing via the open gas duct 114. The one or more fans are configured to continue rotating until manual intervention by an operator of the hydrogen module 1000 occurs (e.g., once an operator of the hydrogen module inspects hydrogen gas concentration readings recorded by the gas detector modules 146a, 146b and determines it is safe to stop extraction).

[0062] The programmable logic control system may also be communicably coupled to the vent 118 shown in Figure 1 B. In event of a hydrogen gas leak within the housing 100 as described above, the vent 118 is opened to allow ambient air to enter the housing 100. As shown by Figure 1 B, the vent 118 may be disposed close to the floor of the hydrogen module 1000 such that ambient air can enter the lower section of the housing 100, such that comparatively light hydrogen pas is purged out of the top of the housing 100 via the gas duct 114 as the housing 100 fills with ambient air. The components of the control system 1020 may receive electrical power from a power supply unit (not shown). The power supply unit may be mounted externally to the housing 100 in order to mitigate the risk of failure of the power supply unit in the event of a fire within the housing 100. The power supply unit may be housed within a protective structure in order to guard the power supply unit against damage from vehicle impacts. In the event of electrical power failure, the first and second solenoid valves 130, 140 default to a closed position for safety purposes.

[0063] Hydrogen gas leaks can lead to the risk of fire within the hydrogen module 1000. A temperature sensor (not shown) may be present in the housing 100 and configured to measure a temperature within the housing. The programmable logic control system may be communicably coupled to the temperature sensor, and, in the event of the temperature within the housing 100 reaching a threshold temperature (such as 60 °C) , the programmable logic control system activates the one or more relays 145 to close the first solenoid valve 130 and the second solenoid valve 140 so that hydrogen gas is prevented from flowing through the gas flow system 1010 and out of the housing 100 via output port 110.

[0064] The housing 100 may additionally comprise a fire suppression system (not shown) that includes a fire extinguishant and a thermally activated element configured to rupture (e.g., melt) under heating. For example, the fire extinguishant may be held within a container within the housing 100, where the thermally activated element forms at least a portion of the container. In the event of a fire within the housing 100 (e.g., due a hydrogen leak) the temperature within the housing 100 will rise, causing the thermally activated element to rupture, triggering the release of the fire extinguishant into the housing 100 to extinguish the fire. The fire suppression system may be mounted directly above the gas flow system 1010 such the gas flow system 1010 is completely covered in fire extinguishant in the event of a fire within the housing 100.

[0065] A controller may be present in the housing 100 (not shown). The controller may be configured to communicate with a warning system 600 located within the vehicle 5000 in order to alert inhabitants of the vehicle 5000 to a fault condition of the hydrogen module 1000, so that the vehicle inhabitants can evacuate the vehicle 5000. The fault condition may be one or more of: a hydrogen gas concentration (as recorded by the one or more gas detector modules 146a, 146b) reaching the hydrogen gas concentration threshold; a temperature within the housing 100 (as recorded by the temperature sensor) reaching the threshold temperature and therefore indicating a fire within the housing 100; and an absence of a gas-tight seal between the lid 102 and the housing 100 (e.g., as detected by an electronic switch mounted on a lid / housing interface). Upon a fault condition being detected by the controller, the controller communicates the fault condition to the warning system to indicate a fault with the hydrogen module 1000 to inhabitants of the vehicle. As shown by Figure 6, the warning system 600 may be positioned with a cabin 506 of the vehicle 5000, and may indicate a fault visually (e.g., through activation of one or more warning lights) and / or audibly (e.g., by sounding an alarm). The fault indication provided by the warning system 600 may differ depending on the type of fault (e.g., a different warning light and / or warning tone may be activated for a hydrogen gas leak compared to a fire). For safety reasons, the controller may be hard-wired to the warning system 600 and / or to the programmable logic control system by a suitable connector, such as a RS232 or RJ45 connector. Alternatively, the controller may be a wireless controller in wireless communication with the warning system 600 and / or the programmable logic control system.

[0066] Module for Supplying Air Gas

[0067] With reference to Figures 7A and 7B, there is illustrated a module 2000 for supplying air gas to a flame ionisation detector.

[0068] As noted above with respect to the hydrogen module 1000, it is not practical to mount the module for supplying air gas 2000 (hereinafter referred to as “the air module 2000”) external to a vehicle in order satisfy the new European vehicle emissions standard (EU7) requirement for measurement of total hydrocarbons during an on-road test. Furthermore, as with the hydrogen module 1000, if the air module 2000 is exposed to ambient temperatures outside of the vehicle, resulting temperature fluctuations in air gas supplied by the air module 2000 could lead to inaccurate hydrocarbon emission measurements. To overcome these safety and data reliability issues, a housing 200 of the air module 2000 is configured to be mounted within a vehicle. One practical solution (shown in more detail by Figure 11) is to mount the air module 2000 within a boot space of the vehicle together with the hydrogen module 1000.

[0069] As shown by Figure 7B, the housing 200 may have a lid 202 connected to the housing 200 by one or more hinges 206. The lid 202 may be fastened against the housing 200 by one or more clasps 204, as shown in Figure 7A, in order to form a lockable, gas-tight, enclosure. The housing 200 may also comprises one or more handles 208 affixed to opposing sides of the housing to facilitate transportation of the air module 2000 into / out of the vehicle.

[0070] The housing 200 comprises an output port 210 mounted through the housing 200, the output port 210 being configured to selectively couple the air module 2000 to a flame ionisation detector such that air gas can delivered from inside the air module 2000 to the flame ionisation detector. The output port 210 may comprise a connector configured to removably couple to a conduit (such as a hose or other suitable piping) to allow the air gas to flow from the air module 2000 to the flame ionisation detector. The output port 210 may be designed so as to avoid natural air accumulation points within the output port 210. The housing 200 may comprise a manual actuation value 212 mounted through the housing 200. The manual actuation valve 212 may be configured to permit the flow of air gas out from the air module 2000 via the output port 210, and configured such that the manual actuation value 212 is only operable when the air module is coupled 2000 to the flame ionisation detector. The manual actuation valve 212 and the output port 210 may be dimensioned so as to provide a substantially laminar flow of air gas therethrough, such that local accumulation of air gas and risk of pressure drops is reduced. Additionally, the provision of a stable laminar flow of air gas to a flame ionisation detector helps to ensure robust hydrocarbon emission data quality. For example, fluctuations in the air gas (and / or hydrogen gas) supply to the flame ionisation detector can lead to changes in the air-to- fuel ratio of the flame ionisation detector, leading to uncalibrated hydrocarbon emission data.

[0071] A pressure relief outlet 216 may be disposed through a side wall of the housing 200, as shown by Figure 7A. The pressure relief outlet 216 may be connected to a gas flow system located within the housing 200 (discussed in more detail below with respect to Figures 8 and 9) and be configured to allow air gas to safely escape the housing 200 and vent into a cabin of the vehicle in the event that air gas pressure within a pressure regulator of the housing 200 reaches a pressure threshold. Typically, the pressure threshold may be approximately 250 Bar gauge of inlet pressure to the pressure regulator.

[0072] The housing 200 may comprise a plurality of walls. Each wall of the plurality of walls may be formed from a plurality of layers. For example, each of the plurality of walls may be formed from a metallic layer sandwiched between a first non-metallic layer and a second non-metallic layer. The thickness of the metallic layer may be less than a thickness of the first non-metallic layer and a thickness of the second non-metallic layer. The metallic layer may be aluminium, and the first and second non-metallic layers may be carbon fibre. For example, a low nickel aluminium alloy of approximately 20- 40 mm thickness may be combined with a carbon fibre layer of approximately 5-15 mm thickness, depending on worst-case mechanical impact tolerances. The skilled person would appreciate that other materials may be suitable (with appropriate thicknesses) such as austenitic grade stainless steel, copper alloy, or some ferritic steels.

[0073] Figure 8 illustrates a side view of housing 200 of air module 2000, and shows view lines A-A and B-B which will be used in subsequent figures to illustrate various internal views of housing 200. Figure 9 shows a cross-sectional view of the housing 200 of air module 2000 as viewed along line A-A of Figure 8. Figure 9 shows the features that would be visible inside the air module 2000 by opening the lid 202 of the air module 2000 and looking down into the air module 2000. The housing 200 comprises a gas flow system 2010. The gas flow system 2010 comprises a gas bottle 220 that contains air gas (such as synthetic air) to be supplied, via the output port 210, to a flame ionisation detector. The gas bottle 220 is rigidly coupled to the housing 200. One or more mounting arms 222 extend from an interior wall of the housing 200. The gas bottle 220 is coupled to the one or more mounting arms 222 such that the gas bottle 220 is rigidly coupled to the housing 200. Whilst Figure 9 shows a pair of mounting arms 222 for mounting the gas bottle 220, the skilled person would appreciate that a single mounting arm could be provided to support the gas bottle 220 and rigidly couple the gas bottle 220 to the housing 200. For example, a single mounting arm having a width spanning substantially the width of the gas bottle 220 may be provided instead of the pair of mounting arms 222 shown in Figure 9. Similarly, the skilled person would appreciate that three or more mounting arms may instead be provided to support the gas bottle 220 and rigidly couple the gas bottle 220 to the housing 200. By extending from an interior wall of the housing 200, the one or more mounting arms 222 provide a region of empty space between the interior wall of the housing 200 and the gas bottle 220. This region of empty space leads to the formation of a crumple zone around the gas bottle 220 such that, in the event of a vehicle impact, the risk of damage to the gas bottle 220 is minimised. One or more straps 224 may be attached to the mounting arms 222 and pass around the circumference of the gas bottle 220 to further secure the gas bottle 220 within the housing 200. The gas bottle 220 may have a 1 litre capacity and be compressed to a pressure of 200 Bar. It will however be appreciated that the gas bottle 220 may be any suitable size, for example, depending on the size of the housing 200 and / or amount of gas needed for the emissions test.

[0074] As shown by Figure 9, the gas bottle 220 may be mounted horizontally within the housing 200 (e.g . , relative to the base of the housing 200 and with respect to a chassis of the vehicle in which housing 200 is placed). By mounting the gas bottle 220 horizontally, the gas bottle 220 can be positioned relatively lower within the housing 200, thereby improving the stability of the air module 2000 because a centre of gravity of the housing 200 is lowered. The stability of the gas bottle 220 (and its associated piping connections) is also increased. The gas bottle 220 may comprise a high-pressure gas valve 228 for controlling the flow of air gas out of the gas bottle 220. Dampening material may be provided between the gas bottle 220 and the housing 200 (e.g., on the one or more mounting arms 222) in order to suppress oscillation of the gas bottle 220 (e.g., as a result of the vehicle being driven on an uneven road surface during hydrocarbon emission testing). The dampening material may also mitigate the risk of damage to the gas bottle 220 in the event of impact. The dampening material may comprise one or more springs, and / or a rubber material. The gas flow system 2010 further comprises a two-stage pressure regulator 236 coupled between the gas bottle 220 and the output port 210 via a first length of piping 237. The two-stage pressure regulator 236 is configured to control a pressure of the air gas received from the gas bottle 220, such that a required pressure of air gas (as dictated by the requirements of the flame ionisation detector) is provided to the output port 210. The two- stage pressure regulator 236 may comprise dials 238a, 238b to provide a visual indication of the hydrogen gas pressure to an operator of the air module 2000. For example, dial 238a may indicate an inlet pressure received from the gas bottle 220 at an inlet of the two-stage pressure regulator 236, and dial 238b may indicate an outlet pressure leaving an outlet of the two-stage pressure regulator 236 to the output port 210. The use of a two- stage pressure regulator (compared to single stage pressure regulator) allows the pressure of the air gas received from the gas bottle 220 to be reduced progressively in two steps instead of one, thereby delivering a more constant air gas pressure to the outport port 210 than would be achievable with a single stage pressure regulator, and mitigating air gas pressure fluctuations from the gas bottle 220. The two-stage pressure regulator 236 may comprise a membrane having a plurality of pores. Each pore may have a pore size such that passage of gas contaminants through the two- stage pressure regulator is substantially prevented, in order to maintain a required purity of the air gas being supplied to the flame ionisation detector.

[0075] Dampening material is provided within housing 200 to suppress oscillations of the gas bottle 220 and the two-stage pressure regulator 236 (e.g., as a result of the vehicle being driven on an uneven road surface during hydrocarbon emission testing). For example, dampening material may be provided between the two-stage pressure regulator 236 and an internal wall of the housing 200, and between the gas bottle 220 and an internal wall of the housing 200. The dampening material may comprise one or more springs, and / or a rubber material. In addition to dampening material, the pressure regulator 236 may be mounted away from walls of the housing 200 to reduce oscillations of the pressure regulator 236.

[0076] The gas bottle 220 and the two-stage pressure regulator 236 are coupled together by a second length of piping 234, the second length of piping 234 comprising a tortuous path. For example, as shown by Figure 9, the tortuous path of the second length of piping 234 (sometimes referred to as “pigtail piping”) may comprise a plurality of bent portions between the gas bottle 220 and the two-stage pressure regulator 236 such that pressure fluctuations in the air gas leaving the gas bottle 220 peter out before reaching the two-stage pressure regulator 236.

[0077] In general, the piping within the housing 200 (including the first length of piping 237 and the second length of piping 234) comprises a material suitable for use with air gas, such that unintended contamination of the air gas is prevented. For example, the piping within the housing 200 may be stainless steel (e.g., 316L austenitic grade). The piping within the housing 200 may also be sized so as to provide a substantially laminar flow of air gas therethrough, in order to mitigate the risk of local pressure fluctuations in the flow of air gas through the gas flow system 2010.

[0078] The air module 2000 may comprise one or more alignment-marker pairs between a given nut (or other suitable fastener) and piping connected thereto. For example, the second length of piping 234 may have a visual and / or tactile marker, and nut 235 may have a corresponding visual and / or tactile marker, which, when aligned, indicate a required mechanical connection tightness between the second length of piping 234 and the nut 235. Like the piping within the housing 200, the corresponding nuts may also be formed from stainless steel (e.g., 316L austenitic grade). As such, when installing or inspecting the gas flow system 2010, an operator can ensure that all components of the gas flow system 2010 are suitably connected together with appropriate mechanical tightness so that air gas leaks are mitigated. The rigid anchoring of the gas bottle 220 to the one or more mounting arms 222 also helps to avoid the transfer of force from vehicle impact events to threaded connections within the housing 200. The skilled person would appreciate that any length of piping and corresponding nut within the housing 200 may be provided with corresponding alignment-marker pairs. For example, the output port 210 may also have a threaded connector, and the first length of piping 237 may be connected to the threaded connector of the output port 210 via a nut, as shown in Figure 9. Figure 9 also illustrates how the first length of piping 237 may be connected to the manual actuation valve 212, and to the output port 210 via a second portion 237’ of the first length of piping 237, so that the passage of air gas from the gas bottle 220 through the gas flow system 2010 is only achieved via actuation of the manual actuation valve 212.

[0079] The two-stage pressure regulator 236 may be coupled to pressure relief piping 242. The pressure relief piping 242 may be coupled to the pressure relief outlet 216 shown in Figure 7A (e.g., via a threaded connector on the two-stage pressure regulator 236 and corresponding threaded nut, and via a threaded connector on the pressure relief outlet 216 and corresponding threaded nut), and allow air gas to be exhausted out of the air module 2000 in the event of failure of the two-stage pressure regulator 236 (e.g., if a diaphragm of the two-stage pressure regulator 236 fails).

[0080] Figure 10 illustrates a cross-sectional view through the housing 200 of the air module 2000 as viewed along line B-B of Figure 9, showing in more detail the two-stage pressure regulator 236 and associated piping. For instance, Figure 10 shows how the pressure relief piping 242 is coupled to the pressure relief outlet 216, and how the second portion 237’ of the first length of piping 237 is coupled to the output port 210. Modular System

[0081] As shown by Figure 11 , the hydrogen module 1000 and air gas module 2000 may be combined with a flame ionisation detector 3000 to form a modular system 4000 for hydrocarbon emission testing. The modular system 4000 may be positioned within a vehicle 5000 to allow for onboard hydrogen carbon emission testing while the vehicle 5000 is moving. The modular system 4000 may be housed, for example, within a boot 500 of the vehicle 5000. Mounting the modular system 4000 in the interior of the vehicle 5000 leads to stable hydrogen and air gas temperatures, which encourages stable flame synergy within the flame ionisation detector, leading to more accurate and reliable hydrocarbon emission testing data.

[0082] To couple the hydrogen module 1000 to the flame ionisation detector 3000, the hydrogen module 1000 may have first external piping 4010 coupled between the output port 110 of the hydrogen module 1000 and a hydrogen gas input port of the flame ionisation detector 3000. As with the piping used within the hydrogen module 1000, the first external piping 4010 may comprise a material suitable for use with hydrogen gas, such that diffusion of hydrogen gas into the boot 500 of the vehicle 5000 is prevented. For example, the first external piping 4010 may be stainless steel (e.g., 316L austenitic grade). More specifically, the first external piping 4010 may be stainless steel (e.g., 316L austenitic grade) braided polytetrafluoroethylene fluoropolymer. To couple the air module 2000 to the flame ionisation detector 3000, the air module 2000 may have second external piping 4020 coupled between the output port 210 of the air module 2000 and an air gas input port of the flame ionisation detector 3000. As with the piping used within the air module 2000, the second external piping 4020 may comprise a material suitable for use with the air gas, such that unintended contamination of the air gas and leaking of the air gas into the boot 500 of the vehicle 5000 is prevented. For example, the second external piping 4020 may be stainless steel (e.g., 316L austenitic grade). In order to mitigate temperature differences between the hydrogen gas and the air gas received at the flame ionisation detector 3000, the first external piping 4010 and the second 4020 may be of equal lengths. Similarly, a combined length of all of the piping contained within the hydrogen module 1000 may be the same as a combined length of all of the piping contained within the air module 2000. In order to mitigate pressure differences between the hydrogen gas and the air gas received at the flame ionisation detector 3000, the first external piping 4010 and the second 4020 may share a common inner diameter. The output port 110 of the hydrogen module 1000 and the output port 210 of the air module 2000 may be configured differently in order to prevent an operator being able to mistakenly couple the hydrogen module 1000 to the air gas input port of the flame ionisation detector, and / or to mistakenly couple the air module 2000 to the hydrogen gas input port of the flame ionisation detector (sometimes referred to as “poka-yoke” considerations). The first external piping 4010 and the second external piping 4020 may each have differently configured couplings such that the first external piping 4010 can only be coupled to the hydrogen module 1000, and such that the second external piping 4020 can only be coupled to the air module 2000. In order to vent hydrogen gas out of the hydrogen module 1000 and out of the vehicle 5000 in the event of a hydrogen gas leak within the housing 100 of the hydrogen module 1000, a conduit 502 (such as a hose) may be coupled to the gas duct 114 of the hydrogen module. The conduit 502 may be affixed through a hole in a door pillar 504 of the vehicle 5000. Sealant may be applied between the hole in the door pillar 504 and the conduit 502 to form a closed system such that no hydrogen gas may leak into the interior of the vehicle 5000. The conduit 502 may alternatively be affixed through a hole in a window 508 of the vehicle. The conduit 502 may comprise a material suitable for use with hydrogen gas, such that diffusion of hydrogen gas into the interior of the vehicle 5000 is prevented. For example, the conduit 502 may be stainless steel (e.g. , 316L austenitic grade) braided polytetrafluoroethylene fluoropolymer.

[0083] It will be appreciated that various changes and modifications can be made to the present invention without departing from the scope of the present application.

Claims

CLAIMS1 . A module for supplying gas to a flame ionisation detector, the module comprising: a housing configured to be mounted within a vehicle, the housing comprising a gas flow system, the gas flow system comprising: a gas bottle for containing gas, wherein the gas bottle is rigidly coupled within the housing via one or more mounting arms extending from an interior wall of the housing; a two-stage pressure regulator coupled to the gas bottle; and an output port mounted through the housing and coupled to the two-stage pressure regulator, the output port configured to supply gas to a flame ionisation detector; wherein the two-stage pressure regulator and the output port are coupled together by first piping; the gas bottle and the two-stage pressure regulator are coupled together by second piping, wherein the second piping comprises a tortuous path; and wherein the housing further comprises a first dampener configured to suppress oscillations of the gas bottle and the two-stage pressure regulator.

2. The module of claim 1 , wherein the first dampener is disposed on the one or more mounting arms.

3. The module of claim 1 or claim 2, wherein the first dampener is provided between the two-stage pressure regulator and an internal wall of the housing.

4. The module of any preceding claim, further comprising a gas detector mounted within the housing, the gas detector configured to detect a gas concentration in the housing.

5. The module of claim 4, wherein the housing further comprises a second dampener provided between the gas detector and an internal wall of the housing.

6. The module of any preceding claim, wherein: the first dampener comprises one or both of a rubber material and a spring; and the second dampener comprises one or both of a rubber material and a spring.

7. The module of any preceding claim, wherein the two-stage pressure regulator comprises a membrane comprising a plurality of pores, each pore having a pore size such that passage of gas contaminants through the two-stage pressure regulator is substantially prevented.

8. The module of any preceding claim, wherein the first piping comprises a tortuous path.

9. The module of any preceding claim, wherein: the output port and the two-stage pressure regulator each comprise first threaded connectors, and wherein the first piping is coupled to the output port and the two-stage pressure regulator via the first threaded connectors; and the gas bottle and the two-stage pressure regulator each comprise second threaded connectors, and wherein the second piping is coupled to the gas bottle and the two-stage pressure regulator via the second threaded connectors.

10. The module of claim 9, further comprising one or more alignment marker pairs configured to indicate a required mechanical connection tightness between one or both of: the first threaded connectors and the first piping; and the second threaded connectors and the second piping.11 . The module of any preceding claim, wherein the first piping, the second piping, the first threaded connectors and the second threaded connectors are formed from 316L austenitic grade stainless steel.

12. The module of any preceding claim, wherein an inner diameter of the first piping and the second piping is sized so as to provide a substantially laminar flow of gas therethrough.

13. The module of any preceding claim, wherein the housing comprises a plurality of walls each formed from a metallic layer sandwiched between a first non-metallic layer and a second non-metallic layers, wherein a thickness of the metallic layer is less than a thickness of the first non- metallic layer and a thickness of the second non-metallic layer.

14. The module of claim 13, wherein the metallic layer is aluminium, and the first and second non-metallic layers are carbon fibre.

15. The module of any preceding claim, wherein the gas bottle is mounted horizontally with respect to a chassis of the vehicle.

16. A system comprising: a flame ionisation detector; a first module according to any of claims 1-15; a second module according to any of claims 1-15.

17. The system of claim 16, wherein a combined length of the first piping and the second piping of the first module is equal to a combined length of the first piping and the second piping of the second module.

18. The system of claim 16 or claim 17, wherein the system further comprises: first external piping coupled between the first module and the flame ionisation detector; and second external piping coupled between the second module and the flame ionisation detector; wherein the first external piping and the second external piping have a common length.

19. The system of claim 18, wherein the first external piping and the second external piping have a common inner diameter.

20. The system of any of claims 16 to 19, wherein the output port of the first module has a different configuration to the output port of the second module.

21. A vehicle comprising the module of any of claims 1 to 15, or the system of any of claims 16 to 20.

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