Woodward\u2019s solenoid-operated gas admission valves (SOGAV) are the well-established \u2018go-to\u2019 for the industry, but they\u2019ve recently had to adapt to new realities.<\/p>\n
To return to basics for a moment, these SOGAVs are a family of electrically actuated, fast-response gas valves for port fuel admission on four-cycle, turbocharged natural gas or dual-fuel engines. They work by pressure loading the metering plate to the \u2018closed\u2019 position; it\u2019s opened on demand by the valve\u2019s e\u2010core solenoid, which has a short travel and high output-force designed to deliver consistent and precise cylinder-to-cylinder control.<\/p>\n
It\u2019s a rather elegant design suited to a broad swath of applications: that\u2019s the reason they\u2019ve been so successful in the past, and why they\u2019re in the frame for the gaseous fuels of the future, Rick Boom of Woodward tells MS.<\/p>\n
But getting everything lined up for the new fuels is by no means straightforward.<\/p>\n
While the IGF-Code came into force in 2017, frankly \u201cthe industry as a whole was just not ready at that moment\u201d, admits Boom. It was especially challenging for the SOGAV design, sitting in the critical \u2018Zone 0\u2019 as described by the IGF Code \u2013 right inside the gas flow.<\/p>\n
Part of the issue was technical: while the code sets the goals for the safety levels required for compliance, it leans heavily on the international IECEx 60079 (explosive atmospheres) standard: this details \u201cthe \u2018how\u2019 and \u2018what\u2019,\u201d he explains.<\/p>\n
However, this standard is primarily designed from a pure explosion risk perspective: according to Boom, creating a marine gas admission valve product that fulfilled the sometimes conflicting criteria pushed the team into \u201clargely unexplored\u201d territory.<\/p>\n
Take apparently simple items such as cable glands or solenoid encapsulation materials: these have to be both compatible with CH4 and also cope with the heat and vibration that comes with the SOGAV\u2019s position right on top the cylinders. \u201cThere were products that looked good on paper but couldn\u2019t survive this environment,\u201d he says, \u201csome of them failing within minutes of initiating a test\u201d.<\/p>\n
Further, just occasionally a suitable alternative couldn\u2019t be found, which meant going right back to the drawing board and devising a solution that could sit within the boundaries of both the IECEx requirement and IGF code.<\/p>\n
Moreover, not many \u2018notified bodies\u2019, (that is, those able to award the necessary listing) had any familiarity with marine engine room conditions. \u201cSo, finding one that was able to help us work out a solution was quite a challenge,\u201d he admits.<\/p>\n
Material compatibility wasn\u2019t the end of the issue: there were also design conflicts.<\/p>\n
For example, Woodward\u2019s SOGAVs have integrated leak detection: this has been developed to address safety concerns around low-flashpoint fuels – but it relies on being accessible from the surface of the double-walled piping. That didn\u2019t sit well with the IECEx requirement which wants the whole thing completely isolated; the notified body wanted the leak detection functionality entirely removed. \u201cClass \u2013 well, they weren\u2019t happy,\u201d says Boom. It was eventually sorted out, but it took work.<\/p>\n
And at this point, others stakeholders come into the mix. Resolving such conflicts might be relatively easy if there\u2019s an unlimited palette of optional extras, but that just not going to wash with the OEMs: their requirement is for valves that sit in the same space, with the same characteristics as before. In short, \u201cneither OEM customers nor class societies wanted to make alterations to proven designs or features\u201d, says Boom: \u201cThey want a tested, fit and functional product\u201d.<\/p>\n
So, compliance been a lengthy business, \u201ctaking many sessions with OEMs, Notified Bodies, CIMAC and IACS before we even settled on the specification and started the design work\u201d, but the concerted effort has paid off.<\/p>\n
It\u2019s not the end of the evolution for either the IGF-Code or Woodward. In fact, a recently emerging fuel has caught the SOGAV team\u2019s attention.<\/p>\n
Ammonia appears to be breaking ahead of the pack because it has better energy density than many of its competitors, and it promises a route forward into power-to-X fuels: \u201cYou hear about ammonia almost daily,\u201d says Boom, pointing out that big players, including Maersk, have been paving the way for take-up. It\u2019s not the only candidate by a long chalk, but \u201clow-pressure ammonia gas admission is a realistic option,\u201d he says, \u201cand we have to make it work\u201d.<\/p>\n
Like others, ammonia will need to be embraced by the IGF Code to become a useful alternative. As such, it has many of the same considerations at other low-flashpoint fuels, explains Boom, who happens to be one of the code\u2019s original architects.<\/p>\n
Interestingly, ammonia \u2013 NH3 \u2013 and natural gas (largely CH4) belong in the same group as far as their flashpoint is concerned, and while combustion characteristics diverge there are useful potential mixes and possibilities for dual-fuel technology crossovers.<\/p>\n
But once again, there are further demands which don\u2019t sit easily with each other, planting manufacturers like Woodward squarely between conflicting requirements.<\/p>\n
Things start to get tricky because SOGAVs need to retain their safety within the aggressively corrosive (and toxic) ammonic atmosphere.<\/p>\n
\u201cWe\u2019ve had to identify potential weaknesses for ammonia operation, and replace them \u2013 especially the elastomers,\u201d says Boom. However, the first problem has been sourcing the alternatives and sadly, there\u2019s been \u201ca fair amount of disappointment\u201d along the way, he adds \u2013 though the team have won through before, so he\u2019s confident they will do so again.<\/p>\n
INSIDE INFORMATION<\/strong><\/p>\n Alternative fuels aren\u2019t the only spur to innovation.<\/p>\n \u201cOur SOGAVs do have a good track record. But there\u2019s a growing focus on things like carbon emissions and methane slip, and this translates into heightened accuracy, a tightening of the mechanical tolerances,\u201d says Boom: that, in turn, can drive up costs. However, he explains another, effective method to help mitigate these growing requirements\u2019 impact is to apply a diagnostic system and electronic support.<\/p>\n That means getting inside information on the operation. The ECU triggers the mechanism on demand, but there\u2019s been no feedback to precisely ascertain how it responds. So, recent developments have added current profile monitoring, which plots exactly when the valve opens and closes.<\/p>\n \u201cA drift in performance \u2013 usually from wear and tear \u2013 can usually be compensated by control algorithms,\u201d says Boom. The new diagnostic element also allows an accurate prediction of the remaining time before it has to be replaced entirely. While these SOGAVs are built for a typical 16,000-24,000 hour life, he comments that \u201cit\u2019s very useful for the operator to know if the valves are good for the next 5,000 hours\u201d.<\/p>\n Finally, Woodward\u2019s SOGAVs are almost ubiquitous but this can be a double-edged sword. As a result of the valve\u2019s market penetration, \u201cwe are dealing with every OEM and every engine, each of which has its specific validation requirements\u201d, he explains, adding: \u201cWe are steadily working our way through them all.\u201d<\/p>\n It\u2019s obviously a protracted, detailed business. However, these adaptations already cover around 99% of all applicable engines between a 17cm and 54cm bore size \u2013 so it\u2019s pretty sure they will be ready to meet the new demands.<\/p>\n Will there now be a pause for breath in the round of modifications? Possibly not \u2013 partly because the industry shows no sign of settling the fuel contest anytime soon: in fact, it might be just beginning, predicts Boom: \u201cThe whole journey toward zero emissions is leading a lot of R&D… there\u2019s a high number of combustion recipes and potential systems, which will have to boil down over time.\u201d This, of course, impacts both material and electronic development of a range of components.<\/p>\n However, \u201cthe SOGAVs\u2019 longevity stems from the company\u2019s efforts to meet the needs of the market\u201d, he concludes. \u201cWe\u2019re always innovating.\u201d<\/p>\n","protected":false},"excerpt":{"rendered":" With new developments come challenges for tried-and-trusted components. Rick Boom of Woodward talks to Stevie Knight.<\/p>\n","protected":false},"author":8,"featured_media":687,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[13],"tags":[],"sponsor":[],"class_list":["post-686","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-equipment"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.motorship.com\/propulsion-and-future-fuels-conference\/wp-json\/wp\/v2\/posts\/686","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.motorship.com\/propulsion-and-future-fuels-conference\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.motorship.com\/propulsion-and-future-fuels-conference\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.motorship.com\/propulsion-and-future-fuels-conference\/wp-json\/wp\/v2\/users\/8"}],"replies":[{"embeddable":true,"href":"https:\/\/www.motorship.com\/propulsion-and-future-fuels-conference\/wp-json\/wp\/v2\/comments?post=686"}],"version-history":[{"count":0,"href":"https:\/\/www.motorship.com\/propulsion-and-future-fuels-conference\/wp-json\/wp\/v2\/posts\/686\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.motorship.com\/propulsion-and-future-fuels-conference\/wp-json\/wp\/v2\/media\/687"}],"wp:attachment":[{"href":"https:\/\/www.motorship.com\/propulsion-and-future-fuels-conference\/wp-json\/wp\/v2\/media?parent=686"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.motorship.com\/propulsion-and-future-fuels-conference\/wp-json\/wp\/v2\/categories?post=686"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.motorship.com\/propulsion-and-future-fuels-conference\/wp-json\/wp\/v2\/tags?post=686"},{"taxonomy":"sponsor","embeddable":true,"href":"https:\/\/www.motorship.com\/propulsion-and-future-fuels-conference\/wp-json\/wp\/v2\/sponsor?post=686"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}