by Thermo 7. March 2011 22:58

Projecting Future Load – Compound Growth

Dear Thermo,

Thanks for your insightful answer in your previous post, “Why does the load matter?  How important is the future load growth?  Our planning team gives me a range instead of a single value; they suggest 2-3%.  I have sent you some real data for several of our circuits.  Teach me oh webbed one!

Still Overworked in Ohio

P.S.  Steve is actually very helpful once you get used to him.

Dear Overworked- 

Albert Einstein is said to have once quipped, “The most powerful force in the universe is compound interest.”  He was talking about money, but the same principle applies to compound growth of any kind as you shall see if you read on.

Your planners undoubtedly consider whether the geography served by the circuit is mature or whether there is still new development likely.  On top of the growth rate from new services, how are existing customer electrical demands changing?  In general, more and more electrical applications are being deployed, but greener, more energy efficient appliances may mitigate or even reverse that load growth.  Also demand management may reduce peak loads.  I picture the planners pulling out their crystal balls to determine how fast plug-in hybrid cars will be deployed.  These are just a few of the considerations in estimating future load growth.  The impact is huge, so the exercise is well worth considering.

To test that impact, let’s do a sensitivity analysis on a single 3-phase feeder circuit, your Carrollton AM-1215.  Nearby, I have plotted estimated temperature data for the circuit for most of 2010 in 30 minute increments.  The lowest curve on this graph is the ambient soil temperature at cable depth.  The temperature of the individual cables for phases A, B, and C, are displayed as fine red, grey and blue lines respectively.  The flux weighted temperature, that is the equivalent constant temperature that provides the same permeation of fluid through a cable, are the three heavy horizontal lines using the same red, grey, and blue color scheme.  I described this process generally in my previous post and I have promised a future post to examine in more detail what flux weighting means.

The next illustration of three graphs stacked on top of each other shows the extrapolation of the Carrollton AM-1215 data with 1%, 2% and 3% annual load growth.  First allow me to explain the common elements of each graph.  The x-axis is the year.  The red, grey, and blue dashed lines are projections of flux weighted amperage for phases A, B, and C respectively.  All dashed lines are plotted against the left-y-axis.  The corresponding flux weighted annual temperatures are like-colored solid lines and are plotted against the right-y-axis.  The top-most horizontal dashed line (purple) at 603 amperes is the rated ampacity of each cable.  The lower horizontal dashed line (violet) at 469 amperes is the maximum flux weighted load.  Based upon the historical difference between the peak and flux weighted temperatures for all three phases, when the flux weighted current grows to be greater than or equal to the flux-weighted maximum load, the circuit will experience significant thermal excursions above the maximum operating temperature during periods of peak load.

In the top graph of 1% annual growth, the cable is approaching its ampacity limit in the year 2050 – 40 years from now.  All is well.  In the middle graph of 2% annual ampacity growth, constraints are experienced in about 2031 or 20 years from now.  The doubling of the growth rate halved the ampacity-life of the circuit.  In the bottom graph of 3% annual ampacity growth, constraints are experienced in about 2025 or 14 years from now.

Einstein was right – the compounded growth rate is the most powerful force in the universe!  The difference between 1%, 2%, and 3% is bigger than my belly.  For the Carrollton AM-1215 circuit, 40 years of life is simply not possible in the 2% and 3% load growth scenarios unless a portion of its load is transferred to another circuit.

If you don’t expect to keep a circuit in service for 40 years, don’t ask Steve to warrant it for that long.  Ask him for a shorter life and a discount.  The cost of the technology to obtain 40 years of life is more than the cost to reach 20 years.

Compounding my own growth,

Thermo

P.S.  As for me I have never really gotten used to Steve.  His skin lacks any camouflage pattern.  I am pleased that you have learned to look the other way.  I will endeavor to be more tolerant.

Tags: , , ,

Rejuvenation Science

by Thermo 24. February 2011 20:52

Why does the load matter?

Dear Thermo,

Why are the folks at Novinium so insistent on knowing the loading of my feeder cables?  This guy named Steve keeps asking me to estimate the load growth.  How am I supposed to do that?  The company we previously employed for rejuvenation never asked.  Is this effort really worth it?  Your NRI20 (Editor’s note:  The gentleman is referring to Novinium Rejuvenation Instruction 20, Tailored Formulation™ & Tailored Pressure™.) step 3 requires that I categorize the load into low, moderate or heavy.  How do I do that?

Overworked in Ohio

Dear Overworked-

There is a reason my first name is Thermo.  Temperature is really important!  Let’s start with a four-step chain of causality …

Chain of causality

1.    Load affects temperature.  (The cable warms as more current flows.)

2.    Temperature affects the permeation rate of rejuvenation fluids.  (Permeation rates for all treatment fluids increase by about a factor of three for each 10°C temperature increase.)

3.    Permeation rate affects how quickly rejuvenation fluid exudes from the cable.  (The faster fluid permeates through polyethylene, the faster it can sweat out of the cable.)

4.    Rejuvenation fluid exudation affects the treatment life extension.  (If the fluid leaves the cable, it isn’t helping it!)

Only Novinium’s patented approach of tailored formulation™ (U.S. Patent 7,611,748) is able to adjust the formulation and quantity of the rejuvenation fluid supplied to mitigate the aforementioned pernicious chain of causality.  That may be why the other guys don’t bother to ask.

Would you like to maximize the life extension your circuits enjoy?  I presume your answer is, “Yes!”  Tailoring the formulation requires just a few pieces of data.  I’ll bet they are fairly easy to come by. 

1.    We already know where you are, so we can use the global soil regime map nearby to estimate the soil temperature at cable depth.  A larger version of the map is also at the aforementioned NRI.  For Ohio the soil is mesic and the temperature at cable burial depth varies from 8 to 15°C.

2.    Based upon your local soil thermal conductivity, provide me with the maximum design load and the corresponding temperature.  In the example that follows these values are 603 amperes and 90°C respectively.

3.    Download some historical load data for the circuit.  The data should have a date and time and load in amperes.  The data should be at least every 6 hours over a one year period, each one hour is even better.  That’s a lot of numbers, but computers excel at this and we have a MS Excel worksheet that makes child’s play of the number crunching.  We then convert the load values to approximate temperatures as shown for example in the nearby graph titled, “Current-Temp Relationship.”  In another nearby graph titled, “Flux Weighted Temperature Estimate,” four days of data are shown for the example circuit.  The historical flux weighted temperature (FWT) is thus calculated.

4.    Next you need to estimate your anticipated annual load growth over the period of the circuit's remaining life.  Don’t let the perfect be the enemy of the good.  Of course, you can’t know precisely what the future load growth is going to be, but your planning process should generate a better estimate than me sitting on a lily pad 1,933 miles away. For this example, the annual load growth is 1.2% and the circuit owner desires 40 years of additional life.

Based upon the Novinium technology embodied in a pair of U.S. Patents titled, “Predicting Performance of Electrical Power Cables,” (U.S. Patents 7,643,977 and 7,848,912) Novinium estimates the prospective FWT.  For our example, the historical FWT is about 15°C and the prospective FWT is 26°C.  The appropriate fluid choice is Ultrinium™732/30.  This cable has a low load.

As for Steve, we actually pay him to be a pest.  Please be nice to him.

Staying flux weighted cool,

Thermo

P.S. At least one of my readers is undoubtedly wondering:  What the heck is Flux Weighted Temperature?  Click on the link to learn more.

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Rejuvenation Science

by Thermo 25. January 2011 17:20

To UV or not to UV

In my December 29, 2010 post at …

Crazy-Competitor-Claims

Wonderer in the Wilderness inquired …

1. How can Novinium get the same cable life extension without a soak period?  It would seem to me that Novinium puts less fluid into the cable than one would get with a soak period.

In my first post addressing this question I provided an abbreviated answer. We learned from the abbreviated answer that that when Novinium founders conceived of the first generation of treatment fluid over two decades ago we failed to check the relative diffusion rates of the phenylmethyldimethoxysilane (PMDMS) monomer and the condensation catalyst we had chosen to provide long life.  This turned out to be a grave mistake, which we have corrected.  In a subsequent post on January 3, 2011 at …

Catalytic Considerations – Component I

… I provided a more comprehensive answer, but I promised five new posts that would explain the functional improvement of the five kinds of ingredients in Ultrinium™ 732 and Ultrinium™ 733 fluids.

In this second of five sub-posts, we will explore the role of the ultra-violet absorbers (UVAs) and hindered amine (pronounced a-mean) light stabilizers or HALS.  The primary UVA is BASF®’s Tinuvin® 1130.  Additionally ferrocene (pronounced fair-O-seen), which was discussed in my last post, Voltage Stabilizer, is not only a voltage stabilizer, but also absorbs ultraviolet photons in the appropriate wave length.  In the vernacular, ferrocene is a “two-fer” or a “two-for-one” ingredient, because it fulfills two independent and important life-extension functions.

As you know, frog skin is very sensitive, and so I slather on the UVA (sunscreen) every time I am out in the sun – doing so helps keep me beautiful.  Cables buried one meter underground do not need protection from the sun’s relentless ultraviolet onslaught.  They do need UV protection, however, from UV that is created when space charges recombine near the ends of water trees.  Consider for example the work of Bamji, Bulinski, Chen and Densley in the Proceeding of the 3rd International Conference on Properties and Applications of Dielectric Materials, held in Tokyo in July 1991:

“… at points of electric stress enhancement in the polymer, the light emitted during the initiation phase of electrical treeing is … due to the recombination of electrons and holes injected into the material.  The spectra of the emitted light is in the visible and ultraviolet ranges.  The ultraviolet light can photodegrade the polymer and lead to electrical treeing.”

It is easy for us all to understand how UVA materials work.  They are opaque to UV light.  The potentially damaging UV photon strikes a resonance stabilized structure in the UVA molecule, is safely absorbed, and is converted to harmless heat.  That’s how sunscreens for our skin work too.  On my skin, if I want to stop 100% of the UV photons I need to apply unattractive zinc-oxide in a thick pasty layer – yuck!  In insulation if I want to stop 100% of the UV photons, I need to apply clay – we call those insulations EPR, EPDM, et al.  So UVA materials cannot intercept 100% of the damaging UV photons.

Unlike the common experience we all have with UVA materials, HALS are not within our normal experience.  HALS are free radical scavengers and they are beneficial, because the mechanism of photodegradation involves the creation of a free radical by errant UV photons – a photon strikes an electron and imparts so much energy to the electron that the molecule, to which it was bound, can no longer hold on to it.  A free radical (an unpaired electron in the molecule) and a free electron are created.  Electrons don’t like to be unpaired, and so, they search out other electrons and try to borrow them from their parent molecules.  As they do this, they tear apart innocent molecules and generally there is still an unpaired electron after the damage from the first encounter.  The free radical survives (or spawns a daughter) and creates cascading systemic damage.  HALS quench free radicals, and here is the cool part, they auto-regenerate to a HALS after they kill the free radical.  How cool is that?  I wish they would make HALS for amphibians, because I could take a HALS pill and snack on crickets all day without worrying about the consequences of free radicals ravaging my DNA.

It gets even better.  The word “synergy” is overused in business circles and promised synergies are often quixotic.  The poster tadpole for synergy is the interaction between UVA and HALS components.  Alone, each has a positive effect on cable life, but together they work better than the sum of their parts – one plus one equals three!  Ultrinium™ 732 and 733 fluids and Perficio™ 011 fluid utilize BASF®’s state-of-the-art Tinuvin® 123 HALS.  As we learned in the previous post, DMDB Doubts, Tinuvin 123 also stabilizes aluminum strand patina, which all but eliminates the potential for strand corrosion suffered by older injection technology.  Tinuvin 123 provides another formulation two-fer.

For over two decades, UVA and HALS have been included in TRXLPE (tree retardant cross-linked polyethylene) formulations.  See for example U.S. Patent 4,870,121, "Electrical Tree Suppression in High-voltage Polymeric Insulation,” September 26, 1989.  With the introduction of Ultrinium™ 732 and 733 fluids, Novinium delivers improved UV stabilization using the best available technology.  Novinium’s UV package is protected by U.S. Patent 7,658,808 and other pending patents and their foreign equivalents.  Only Novinium rehabilitation technology provides UV stabilization in the proper UV range.  To learn how first generation technology fails to address the UV photons created by space charge recombination, see Section 8 of the CIGRÉ Canada paper of October 18, 2010, “Cable Rejuvenation Mechanisms: An Update.”

To UV or not to UV, that is the question.  Answer:  Come out of the sunlight into the shade; live longer and with greater reliability,

Thermonuclear

by Thermo 14. January 2011 16:58

Voltage Stabilizer

 In my December 29, 2010 post at …

Crazy-Competitor-Claims

Wonderer in the Wilderness inquired …

1. How can Novinium get the same cable life extension without a soak period?  It would seem to me that Novinium puts less fluid into the cable than one would get with a soak period.

In my first post addressing this question, I provided an abbreviated answer. We learned from the abbreviated answer that that when Novinium founders conceived the first generation of treatment fluid over two decades ago, we failed to check the relative diffusion rates of the phenylmethyldimethoxysilane (PMDMS) monomer and the condensation catalyst we had chosen to provide long life.  This turned out to be a grave mistake, which Novinium has corrected.  In a subsequent post on January 3, 2011 at …

Catalytic Considerations – Component I

… I provided a more comprehensive answer, but I promised five new sub-posts that would explain the functional improvement of the five kinds of ingredients in Ultrinium™ 732 and Ultrinium™ 733 fluids.

In this first of five sub-posts we will explore the role of voltage stabilizers and partial discharge suppressers, geranylacetone (pronounced ger-an-ILL-ass-e-tone) and ferrocene (pronounced fair-O-seen), which are included in all Ultrinium™ fluids.

Ketone-type (pronounced KEY-tone) voltage stabilizers like geranylacetone have been studied in depth by several researchers.  Most prominent among those researchers is Johann Wartusch.  His work culminated in German patent DE 3017442 of August 3, 1983 and is described in his paper “Increased Voltage Endurance of Polyolefin Insulating Materials by Means of Voltage Stabilization” (IEEE 1980).  Wartusch demonstrated that the presence of geranylacetone increased tree inception voltage over three-fold, and due to its affinity for the polymer, it persists in the insulation for many years.

EPRI studied the tree inhibition properties of ferrocene in TD-145 EPRI Project RP 7830-1, “A new class of additives to inhibit tree growth in solid extruded cable insulation” of March 25, 1976, and concluded:  “Ferrocene completely suppresses treeing and increases the breakdown strength of polyethylene by [at least] 100%.”  Kato and his colleagues obtained similar results and the culmination of their effort was U.S. Patent 3,956,420, Polyolefin (pronounced poly-OLE-e-fin) Composition for Electrical Insulation, May 11, 1976.

In short, geranylacetone and ferrocene are proven tree retardants that can each provide 100% improvements in the dielectric breakdown strength of polymers in which they are dispersed.  Both materials persist in treated insulation for decades and both are found only in Novinium® rejuvenation fluids.  The use of ferrocene in rejuvenation fluids is protected by Novinium's U.S. patent 7,658,808 and its foreign equivalents.  Other patents are pending.

Occasionally in polymeric insulation, free electrons are created by one of two known mechanisms.

1.    Recombinant space charges near the tips of water trees may generate enough energy to knock electrons out of their orbitals.

2.    Cosmic ray bombardment is the second source of ionization energy that can create free electrons.  For a 1 mm3 cavity such ionization is likely to occur every five minutes. (See Boggs, “Partial Discharge in the Context of Distribution Cable Testing”, ICC minutes.)

Whatever the source of the free electron, in the absence of a voltage stabilizer, the electron will almost certainly be accelerated by the electrical field and may inflict damage to the surrounding polymer.  Voltage stabilizers scavenge these free electrons and let them resonate within their structure.  The resonation allows the excess energy of the electron to be bled off in small, non-damaging quanta. (i.e. infrared photons, which do not have enough energy to damage the polymer.)  When a suitable and stable receptor for the electron (most likely a cation [pronounced KAT-eye-on] generated when the electron was knocked out of its orbital) is found, the voltage stabilizer gives up the excess electron and returns to its original state, ready to deal with the next errant electron.

Stable and able,

Thermonuclear

Tags: , ,

Crazy Competitor Claims | Rejuvenation Science

by Thermo 7. January 2011 19:22

DMDB Doubts

In my December 29, 2010 post at …

Crazy-Competitor-Claims

Wonderer in the Wilderness inquired …

Question 5. A new fluid, DMDB, has been introduced.  Will this improve injection performance on my URD cables?

In that first post I provided an abbreviated answer.  We learned from the abbreviated answer that DMDB is not appropriate for URD cables in particular, because of two inherent inefficiencies.  One inefficiency is by design; the other … well it’s not by design.  I illustrate the first problem nearby.  We call this property of the fluid, “stoichiometric efficiency.”  (Pronounced stoyk-E-O-meh-tric)

Stoichiometry defines the quantitative relationships that exist between the reactants and products in chemical reactions.  When any of the six monomers in the figure nearby react with water they form desirable products and some undesirable by-products.  The percentage of desirable products compared to the total is the stoichiometric efficiency.  The stoichiometric efficiency can be calculated knowing only the chemical composition.  In the graph titled “Hydrolyzate Concentration in Condensate,” this math has been performed for all alkoxysilanes of commercial significance as a function of the number of alkoxy carbon atoms, from one to twelve.  The six globally significant alkoxysilanes are each illustrated on the figure and their positions within the hydrolyzate concentration continuum are pinpointed.  The table nearby defines the acronyms and provides commentary on each monomer.

Acronym

Long name

Comment

TEMDMS

tolylethylmethyl dimethoxy silane

silane in Ultrinium™ 732 fluid produces about 26% of the undesirable by-product methanol

CBMDMS

cyanobutylmethyl dimethoxy silane

silane in Ultrinium™ 732 fluid produces about 31% of the undesirable by-product methanol

PMDMS

phenylmethyl dimethoxysilane

silane in CableCURE®/XL fluid and Perficio™ 011 fluid produces about 32% of the undesirable by-product methanol

DMDBS or DMDB

dimethyl dibutoxysilane

silane in CableCURE®/DMDB fluid produces about 65% of the undesirable by-product butanol

TEMDOS

tolylethylmethyldi(2-ethylhexoxy)silane

silane in Ultrinium™ 733 fluid produces about 57% of desirable 2-ethyl-hexanol - an effective tree retardant

CBMDOS

cyanobutylmethyldi(2-ethylhexoxy)silane

silane in Ultrinium™ 733 fluid produces about 63% of desirable 2-ethyl-hexanol - an effective tree retardant

 

Methanol, a one-carbon alcohol, is an undesirable by-product of the first three fluids, which are generally deployed in small diameter URD cables.  At very high operating temperatures (i.e. conductor temperatures above 55°C), methanol can corrode aluminum.  Fortunately, the methanol generally diffuses out of the system very quickly and small diameter cables do not routinely experience 55°C conductor temperature.  As a consequence the risk of methanolic corrosion is quite low in applications where these fluids are properly deployed.  All Novinium fluid formulations include Tinuvin® 123, which stabilizes the patina on aluminum strands and further reduces the risk of methanolic corrosion.  Patina (pronounced pa-TEE-na), is the natural corrosion resistant coating that forms on metals such as aluminum.

To address methanolic corrosion in larger conductor cables CableCURE®/DMBD fluid was introduced.  DMDB’s undesirable by-product is butanol, a four-carbon alcohol.  The good news is that butanol is unlikely to cause aluminum to corrode; the bad news is that it comes at the price of stoichiometric efficiency.  In the figure nearby, I have circled in blue the portions of the silane monomers, which yield undesirable by-products.  For the DMDBS monomer, about two-thirds of the molecule provides no benefit to the cable.  Because of its low stoichiometric efficiency, you won’t find this frog suggesting that it be used for small diameter cables – especially when there are much better solutions in wide commercial application.

How about larger conductor cables?  Does DMDB do the trick with those?

In the 1980’s the guys at Du Pont discovered that alcohols with 6 to 24 carbon atoms are “tree growth inhibitor[s] capable of imparting at least a thousand-fold increase in electrical endurance as measured by an accelerated test procedure.” (See U.S. Patent 4,206,260.)  In the figure nearby my green laser is pointing to a lightly-green-shaded region of the graph that falls within the Du Pont discovery.  Instead of undesirable by-products, these longer-carbon-chain alcohols are superb dielectric enhancement fluids.  In other words, with Novinium’s Ultrinium™ 733 fluids there are no undesirable by-products, and hence the stoichiometric efficiency is 100%.  Like the 4-carbon alcohol by-product of DMDBS, the 8-carbon alcohol will not corrode the aluminum.  High performance – no compromises!

Finally, to get the total efficiency, it is necessary to consider other efficiencies including catalytic efficiency.  In my January 3, 2011 post, Catalytic Considerations – Component I, I shed some frog wisdom on that subject.  There is also a technical paper in the Novinium library titled Considerations for Injecting Cable with High Conductor Temperature, which provides even more detail.  The bottom line is DMDBS is definitely not appropriate for small conductor URD cables.  For large conductor cables the best choice is Ultrinium™ 733 fluid which enjoys 100% stoichiometric efficiency and a much higher catalytic efficiency.

Always state-of-the-art,

Thermonuclear Bull Frog

Tags: , ,

Crazy Competitor Claims | Rejuvenation Science

by Thermo 5. January 2011 22:55
Catalytic Considerations – Component II
In my December 29, 2010 post at …
Wonderer in the Wilderness inquired …
Question 1. How can Novinium get the same cable life extension without a soak period?  It would seem to me that Novinium puts less fluid into the cable than one would get with a soak period.
In that first post I provided an abbreviated answer.  On January 3, 2011 a second post at …
… provided the first portion of a more comprehensive answer.  We learned from the abbreviated answer that that when Novinium founders conceived of the first generation of treatment fluid over two decades ago we failed to check the relative diffusion rates of the PMDMS monomer (phenylmethyldimethoxysilane) and the condensation catalyst we had chosen to provide long life.  In the first component of the comprehensive answer we learned about the unfortunate shortcoming of the first generation catalyst.  In this last post I will reveal the secret behind the new generation of catalyst that elegantly solves the problem of premature exudation.  (Not to be confused with the malady suffered by some human males.Embarassed)  The solution, protected by U.S. Patent 7,700,871 and other still pending applications, is a material called DDBSA or dodecylbenzenesulfonic acid.  A chemical representation of DDBSA is illustrated nearby.  Based upon what we learned in the previous post, and at first glance, DDBSA's large size would imply a slow catalyst diffusion coefficient and the same problem suffered by the older approach.  But looks can be deceiving.  I am living proof of that old aphorism.
It is necessary to study DDBSA more carefully.  The “H” in the DDBSA molecule (on the top left corner) is a loosely held hydrogen atom or a proton.  The DDBSA generously shares this proton with silane and siloxane materials.  In the example illustrated, the DDBSA protonates (pronounced pro-toe-nayts) the PMDMS (phenylmethyldimethoxysilane).  That is, the hydrogen moves from DDBSA and resides on the PMDMS molecule as shown by the curved arrow.  This reaction yields a negatively charged DDBSA cation (pronounced cat-ion) and a protonated PMDMS molecule.  The protonated PMDMS molecule is capable of catalyzing its own condensation reaction and that of its neighbors.  The molecular weight of the PMDMS increases from 182.3 to 183.3, an inconsequential 0.5% mass increase, and the molecular radius remains virtually unchanged.  In other words, the protonated PMDMS diffuses right along with its unprotanted brethren and catalyzes their condensation.  While the example provided illustrates the PMDMS molecule included in Perficio™ 011 fluid, the same principle applies to the tolylethylmethyldialkoxysilanes (TEMDAS) included in the Ultrinium™ 732 and 733 fluids.  Ultrinium fluids have one other catalytic surprise.  Each of these fluids includes a cyanobutylmethyldialkoxysilane (CBMDAS), which is autocatalytic.  That is, CBMDAS condenses without the need for any catalyst.
With catalyst and monomer diffusion perfectly matched, the catalytic efficiency for Perfico 011, Ultrinium 732, and Ultrinium 733 fluids is 98% or better.  Plus there is a bonus.  The DDBSA cation not only delivers the catalytic proton to the formulation, it is a potent tree retardant itself.  The Perficio and Ultrinium formulations includes several of these "two-fors."  That is, a single component that delivers two functions for the price of one.  In subsequent posts I will share more two-fors.
Catalyzing conversation,
Thermonuclear

Tags:

Crazy Competitor Claims | Rejuvenation Science

by Thermo 3. January 2011 21:20

Catalytic Considerations – Component I

In my December 29, 2010 post at …

Crazy-Competitor-Claims

Wonderer in the Wilderness inquired …

1. How can Novinium get the same cable life extension without a soak period?  It would seem to me that Novinium puts less fluid into the cable than one would get with a soak period.

In the previous post, I provided an abbreviated answer; in this post I will provide a more comprehensive answer.  We learned from the abbreviated answer that when Novinium founders conceived of the first generation of treatment fluid over two decades ago, we failed to check the relative diffusion rates of the phenylmethyldimethoxysilane (PMDMS) monomer and the condensation catalyst we chose to provide long life.  In the figure nearby, I show diffusion data that demonstrate that the monomer diffuses about six times faster than the catalyst.  I also show two-dimensional scale representations of these two molecules.   From what we learned in Size Does Matter, one can see that the larger and less flexible titanium(IV) isopropoxide (TIP) molecule would diffuse slower than the PMDMS and it does.

This diffusion mismatch was a tragic mistake, because the monomer does not condense to a longer molecule in the absence of a catalyst.  As a consequence, a substantial portion of the PMDMS diffuses out of the cable shortly after injection without adding to the long-term reliability of the cable.  In fact, about 39% diffuses out prematurely.  This premature exudation is caused by catalytic inefficiency.  We cleverly fixed that problem with U.S. Patent 7,700,871, and I will explain the elegance of that solution in a subsequent post in this series …

Catalytic Considerations – Component II

It isn’t just how much fluid is delivered to the cable strands.  Even more important than the fluid quantity injected are:

1.    The amount of fluid that persists in the cable insulation over its post-injection life, and

2.    The capabilities of the molecules that are delivered to …

a.    interfere with the growth of water trees,

b.    interrupt the conversion of water trees to electrical trees, and

c.    disrupt the inception of partial discharges.

However, it is true that when using Unsustained Pressure Rejuvenation (UPR), more fluid can be delivered into the cable strands with longer soak periods.  Novinium is not dead-set against soak periods.  We employ soaking for special cases.  For example, we sometimes employ a soak period on submarine cables with constrained geometries.  A soak period, however, to compensate for a catalyst error is unforgiveable.  Soak periods compromise safety and operational efficiency and should only be utilized where technical or economic considerations preclude the use of sustained pressure rejuvenation or for unusual cases such as the aforementioned constrained geometry submarine cable.  The figure nearby provides a summary of laboratory measurements of the amount of PMDMS fluid that is supplied during a typical 60-day soak period for 1/0 AWG and No. 2 AWG cables.  Each experiment was performed in triplicate.  The amount of PMDMS provided during the soak period is about the same as the amount of fluid lost from catalytic inefficiency.  Perficio™ 011 fluid uses a patented catalyst system that enjoys a 2% catalytic inefficiency compared to the 39% inefficiency suffered by the TIP catalyst.  Therefore, Perficio fluid delivers about the same amount of active ingredient in the cable insulation without a soak as the older technology delivers with a 60-day soak period.

An even better option is to use Ultrinium™ 732 fluid, which not only uses the same state-of-the-art catalyst used by Perficio, but also includes five other ingredient types (both water reactive and not water reactive), which all increase cable life well beyond that possible with the venerable PMDMS fluid utilized in the Perficio formulation.  In future posts, I will examine each of these ingredients in more detail to shed light on how they function to extend cable life.  The table nearby will be updated to provides the links to the post for each of the five ingredient types.

 

Short Name

Long name

Comment

Link

GA

geranylacetone

voltage stabilizer and PD suppression in Ultrinium™ 732 fluid

Voltage Stabilizers

Ferrocene

ferrocene

voltage stabilizer and PD suppression and UVA in all Novinium® fluids

TEMDMS

tolylethylmethyldimethoxy silane

silane in Ultrinium™ 732 fluid

Chain

Entanglement

CBMDMS

cyanobutylmethyldimethoxy silane

silane in Ultrinium™ 732 fluid

Really Long-term Life

KV10

Irgastab® Cable KV10

anti-oxidant in Ultrinium™ 732 fluid

AO, AO

T1130m

Tinuvin® 1130 monomer

UVA in Ultrinium™ 732 fluid

To UV or not to UV

 

T1130d

Tinuvin® 1130 dimer

UVA in Ultrinium™ 732 fluid

T123

Tinuvin® 123

HALS and methanolic corrosion suppression in Ultrinium™ 732 and Perficio™ 011 fluids

In the mean time check out Cable Rejuvenation Mechanisms: An Update from the 2010 CIGRÉ Canada Conference on Power Systems.

Smarter each day,

Thermonuclear

by Thermo 31. December 2010 13:56

 Commercially important rejuvenation molecules arranged from fasted to slowest diffusionSize Does Matter (but so do shape, rigidity and polarity)

In my December 29, 2010 post at … 

Crazy-Competitor-Claims

Wonderer in the Wilderness inquired …

3.  Isn’t it better to have a 100% reactive fluid?  I understand that not all of the Novinium fluid components are water reactive.  When all the fluid components are reacting with water, it seems like you should get better cable rejuvenation.

In this post I will provide a more comprehensive answer.  We learned from the abbreviated answer that water reactivity per se is a short-lived phenomenon and that the data provided by those who now croak of the importance of water scavenging confirms this is so.  The water reactive functionality is gone in about two months for a 1/0 AWG conductor, it would last somewhat longer in bigger cable, but shorter still in a No.2 AWG cable.  For decades-long life extension water reactivity over a couple of months has little direct impact.  If water is not kept out by chemical reaction, how is it excluded?  “Excluded” is such an absolute term and the second law of thermodynamics precludes such an absolute, but we can greatly reduce the quantity of water by preferential solubility.  All of the components of all rejuvenation fluids are more soluble in the polymeric insulation than water.  There is a finite amount of space between the amorphous polymer chains that constitute cable insulation.  If those spaces are preferentially filled with rejuvenation fluid, there is that much less room for water.  Furthermore the chemical properties of well chosen rejuvenation components can mitigate water damage even if there is some water present.  Water is such a small molecule with such a large diffusion coefficient (See the nearby Figure.) that even if one could temporarily react with all of the water in the cable it would be back in a few short days.  For a comprehensive understanding of the molecular thermodynamics of water in cables see …

IEEE-Molecular Thermodynamics of Water in Direct-Buried Power Cables

The real goal of including water reactivity in the formulation is to increase the size of the silane treatment components so that they diffuse slower once they get into the insulation. Slower diffusion means that the rejuvenation component is slower to exude out of the cable into the soil where it obviously provides no benefit.  The suggestion of those who croak for 100% water reactivity is that if it doesn’t react, then it will exude.

Nothing could be further from reality.  The only way to know how fast a component will migrate and exude from a cable is to make measurements of diffusion and solubility.  At Novinium we have made thousands of such measurements.

Does size matter?  Sorry boys, but yes it does.  In general, the bigger the molecule the slower it diffuses, but size is only one of several parameters.  In the Figure nearby I show to scale, two-dimensional representations of the non-catalytic components used in all URD treatment fluids.  (I will deal with catalyst in a separate post and with feeder fluids in yet another post.)  I have arranged the components from the fastest to diffuse to the slowest to diffuse.  At first glance, the bigger the molecule the slower it diffuses, but that isn’t always the case.  Included in the Figure alongside each molecular model is a short name for the component, its molecular weight (the absolute mass of a single molecule), and the approximate diffusion coefficient at 55°C (cm2/s).  Some of the other factors that affect diffusion include the shape of the molecule, the flexibility/rigidity of the molecular structure, and its dipole moment (or internal charge imbalance).  For a molecule to move through the insulation polymer it has to squeeze through very small spaces.  Side chains and protrusions such as those designed into many of the molecules we use at Novinium improve longevity versus the more svelte molecules used in the first generation of technology. 

Name in Figure

Long name

Comment

Water

water

ubiquitous

MeOH

methanol

hydrolysis by-product

TMMS

trimethylmethoxysilane

silane in CableCURE™/XL fluid

PMDMS

phenylmethyldimethoxysilane

silane in CableCURE®/XL fluid and Perfico™ 011 fluid

2-ethyl-hexanol

2-ethyl-hexanol

fast-to-diffuse component in Ultrinium™ 732 and Perficio™ 011 fluids

GA

geranylacetone

voltage stabilizer in Ultrinium™ 732 fluid

TEMDMS

tolylethylmethyldimethoxy silane

silane in Ultrinium™ 732 fluid

CBMDMS

cyanobutylmethyldimethoxy silane

silane in Ultrinium™ 732 fluid

KV10

Irgastab® Cable KV10

anti-oxidant in Ultrinium™ 732 fluid

PMH6

phenylmethylsiloxane hydrolyzate (linear DP6)

typical reaction product of PMDMS

TEMH6

tolylethylmethylsiloxane hydrolyzate (linear DP6)

typical reaction product of TEMDMS

Ferrocene

ferrocene

PD suppression and UVA in all Novinium® fluids

CBMH6

cyanobutylmethylsiloxane hydrolyzate (linear DP6)

typical reaction product of CBMDMS

T1130m

Tinuvin® 1130 monomer

UVA in Ultrinium™ 732 fluid

T1130d

Tinuvin® 1130 dimer

UVA in Ultrinium™ 732 fluid

T123

Tinuvin® 123

HALS and methanolic corrosion suppression in Ultrinium™ 732 and Perficio™ 011 fluids

Ferrocene is an example of a small molecule with an anomalously small diffusion coefficient.  Its rigidity and shape provides its anchor.  KV10 stays in the cable much longer than suggested by its 10-8th diffusion coefficient.  KV10 was designed with two long carbon-chain arms, which are highly soluble in the insulation polymer, to anchor it in place and reduce what cable manufactures that use KV10 call "sweat-out."  PMH6 has been in use for over two decades and enjoys long life in a cable.  Any component below PMH6 lasts even longer.  The smaller the diffusion coefficient, the longer it sticks around.  The five bottom components are the non-water reactive components, but they enjoy the longest life.

Exposing the truth,

Thermonuclear

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Crazy Competitor Claims | Rejuvenation Science

by Thermo 29. December 2010 17:07

Crazy Competitor Claims

Dear Thermonuclear Bull Frog,

I recently attended a webinar on cable rejuvenation presented by another firm and need to ask some questions:

1.    How can Novinium get the same cable life extension without a soak period?  It would seem to me that Novinium puts less fluid into the cable than one would get with a soak period.

2.    The ’840/’841 patents prevent anyone from using a fluid that diffuses into the insulation quickly.  Do Novinium fluids infringe on those patents?  Won’t a fluid with faster diffusion and reactive fluids lead to faster and better treatment of the cable?

3.    Isn’t it better to have a 100% reactive fluid?  I understand that not all of the Novinium fluid components are water reactive.  When all the fluid components are reacting with water, it seems like you should get better cable rejuvenation.

4.    I see that Novinium uses an acid catalyst in their fluids.  Won’t this acid damage the cable, be dangerous to handle, or cause environmental problems?

5.    A new fluid, DMDB, has been introduced.  Will this improve injection performance on my URD cables?

Wonderer in the Wilderness

Dear Wonderer-

Wow, five questions in one inquiry!  That’s a record for this frog.  I like prolific questioners Mr. Wonderer, but some in my audience have short attention spans, so here is what I am going to do.  In this post, I will clarify some of your questions and provide abbreviated answers.  In the next few weeks I will expand on each of the answers.  When I do that, I will come back here and edit this post to include a link to the comprehensive answer.

First let me say that the technology utilized by the folks on the other end of the webinar was largely invented by Novinium founders.  If you want to use that technology, we will take it as a compliment that even our two-decade old ideas still have frog legs.

1.    You wrote:  How can Novinium get the same cable life extension without a soak period?  It would seem to me that Novinium puts less fluid into the cable than one would get with a soak period.

a.    Abbreviated answer:  When Novinium founders invented the technology that utilizes a soak period, we had never measured the relative diffusion rates of the catalyst and the monomer.  When we made that measurement a few years ago, we were a little embarrassed to learn that the previously chosen catalyst diffuses about six-times slower than the monomer.  This mismatch means that for a typical 15kV cable with a 1/0 AWG conductor, more than one-third of the fluid supplied to the cable prematurely diffuses out without undergoing the required condensation reaction.  We call this unfortunate condition, catalytic inefficiency.  As soon as the Novinium science team recognized this problem, we fixed it.  It turns out that in a typical 60-day soak period about one third more fluid is supplied, which just about makes up for the catalytic inefficiency.  Novinium patented our solution (U.S. Patent 7, 700,871).  Now, if you are enamored with soak periods and don’t mind the safety compromises and economic consequences that they entail, we can do soak periods too.

b.    Comprehensive answer:  See Catalytic Considerations - Component I and Catalytic Considerations - Component II

2.    You wrote:  The ’840/’841 patents prevent anyone from using a fluid that diffuses into the insulation quickly.  Do your fluids infringe on those patents?  Won’t a fluid with faster diffusion and reactive fluids lead to faster and better treatment of the cable?

a.    Abbreviated answer:  Ouch!  Suggesting to a circuit owner that a competitor is engaging in patent infringement is not a tactic we would use.  The short answers to both parts of this question are:  No and no.  The second half of the questions about size (i.e. faster diffusion) and water reactivity are addressed by question 3 below.

b.    Comprehensive answer:  See Size Does Matter.

3.    You wrote:  Isn’t it better to have a 100% reactive fluid?  I understand that not all of the Novinium fluid components are water reactive.  When all the fluid components are reacting with water, it seems like you should get better cable rejuvenation.

a.    Abbreviated answer:  No!

                                       i.    I know who suggested this to you, so let’s check out what he wrote to learn if 100% water reactivity really is important:  “The presence of the water reactive functionality phenylmethyldimethoxysilane within the insulation was confirmed by microscopic infrared spectroscopy (SiOMe band at 1190 cm-1) through 54 days.  It should be noted that 1/0 AWG size cable has a small conductor interstitial volume compared to the volume of polymer surrounding.  Larger diameter conductor cables would be expected to have considerably more water reactive functionality present for dielectric enhancement over a longer period.”  [Don Kleyer & Wayne Chatterton, The Importance of Diffusion and Water Scavenging in Dielectric Enhancement of Aged Medium Voltage Underground Cables, Proceedings of the IEEE/PES Conference April 1994.]

                                      ii.    Allow me to translate.  The water reactive functionality is gone in about two months, but it would last somewhat longer in bigger cable, but shorter still in say, a No.2 AWG cable.

                                    iii.    For decades-long life extension, it is quite a stretch to suggest that water reactivity over a couple of months is critical.  But, if you want to believe what the author says now, rather than what his experiments previously indicated, we will make a special 100% water reactive fluid for you.  You see, Novinium has a patent (U.S. Patent 7,611,748) on a process of tailoring the fluid formulation to your unique conditions.  We will make a special brew just for you.  We can name it Ultrinium™/WC.  You might think that “WC” are the initials of the water reactivity proponent, but it stands for Water-reactive Confusion.

b.    Comprehensive answer:  See Size Does Matter.

 

4.    You wrote:  I see that Novinium uses an acid catalyst in their fluids.  Won’t this acid damage the cable, be dangerous to handle, or cause environmental problems?

a.    Abbreviated answer:  I notice that you use an acid in your salad dressing – vinegar.  I notice that you squeeze acid on your fish – lemon juice!  I think the webinar presenter is jealous of our U.S. Patent 7,700,871. We use less than 0.3%, less than 3 parts per thousand of a very large acid molecule called DDBSA.  The acid part of the large DDBSA molecule is 1 part in 332.  In other words the concentration of the acid proton is about 1 part in 111,000!  That’s like putting a teaspoon of vinegar in your bath water.  So no, there is no issue.  The same cannot be said of titanium(IV) isopropoxide (TIP), which is the catalyst used in the two-decade-old technology at a level of 2 parts per 1000.  TIP catalyzes the methanolic corrosion of aluminum.  TIP doesn’t taste good on salad or on fish either.

b.    Comprehensive answer:  The dilute acid will not damage the cable.  It has been deployed in millions of cable feet.  The dilute acid is not dangerous to humans or amphibians.  The acid catalyst enjoys profound benefits.  See Catalytic Considerations - Component I and Catalytic Considerations - Component II to learn more.

5.    You wrote:  A new fluid, DMDB, has been introduced.  Will this improve injection performance on my URD cables?

a.    Abbreviated answer:  No way!  Did the guy actually suggest that?  The active portion of DMDB is diluted by the presence of two 4-carbon alkoxy groups that serve no purpose other than to mitigate the aforementioned methanolic corrosion issue.  Fully two-thirds of the fluid is lost even before suffering the catalytic inefficiency of 60%!  Without a multi-year soak period, one could not hope to get enough DMBD into a URD-size cable to provide multi-decade life.  Rather than diluting the product to solve the corrosion problem, the other guys should switch to an acid catalyst.  Oops, they can’t, because we invented and patented that.  (U.S. Patent 7,700,871)

b.    Comprehensive answer:  See DMDB Doubts

Come out of the wilderness into the light.  The truth is well documented.  I don’t mind setting the record straight – that is what I do for a living.  I am not above having a little fun myself though, so I would like to ask a favor of you.  Wonderer, I would like to plant a question for you to ask the next time you participate in a wilderness webinar:  "Why was Novinium the only firm to participate in NEETRAC’s side-by-side rejuvenation test?"  All rejuvenation vendors were invited.  Instead of casting stones in webinars they could have put their technology directly against the technology leaders.  Here is the answer relayed by NEETRAC in a project conference call:  "[The invited supplier] chose not to participate citing 'business and commercial reasons.'”  Satisfied?

Concluding Crazy Competor Claims,

Thermonuclear

P.S.  I decided to create a whole new category within my blog to address Crazy Competitor Claims.  It will be like a rejuvenation myth busters!  I will print all civil responses from other rejuvenation suppliers, if they want to engage in a public debate on the merits of the various technology choices.  The other guys are big fans of mine; they visit this blog all the time.  I suspect they will cite “business and commercial reasons” for not engaging in a transparent dialog.

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Crazy Competitor Claims

by Thermo 18. December 2010 16:07

How long does rejuvenation fluid stay in the cable?

Dear Froggy,

How long do the silanes stay in a cable when they are injected?  What is the concentration of the resulting siloxanes across the radius of the insulation?

Alaskan Amber

Dear Amber-

Every single cable is unique.  First there are hundreds of possible geometries including different conductor sizes, three different strand compactions, different insulation polymers and thicknesses, jacketed and unjacked, to name a few.  On top of that there is the thermal profile of soil in which the cable is buried.  The difference between the soil temperature at one meter in depth between Alaska (Cryic soils are light blue in color in the image nearby from the U.S. Department of Agriculture.) and Arizona (Hypothermic soils are the orange color.) is about 20°C.  That 20°C makes a difference of about a factor of three on how fast the fluid permeates from the cable!  The cooler temperature in Alaska makes it easier to obtain multi-decade life extension compared to a similar cable buried in the Arizona desert.  Finally each cable is loaded differently and hence its operating temperature and temperature profile is entirely unique.  In the video, nearby, my collegue describes one of the infinite number of cases to illustrate the general idea.  Novinium has done thousands of such simulations in order to arrive at the formulations for its Ultrinium line of products.

Finite Volume Simulation of Cable over 40 years.

 

The cable is an unjacketed 15kV (175 mils of XLPE), a 1/0 concentric stranded conductor buried in mesic soil, and lightly loaded.  The method for performing this simulation is protected by U.S. Patents 7,643,977 and 7,848,912.  The simulation simultaneously solves the chemical reaction kinetics and the permeation dynamics.  The model has demonstrate robust soltions which are within 5% of experimentally measured values.

 

 

At Novinium we use a patented process (U.S. Patent 7,611,748) to tailor the chemistry to the unique circumstances of each circuit owner and indeed to each cable.  No other firm in the world can tailore formulations to optimize performance.  Novinium does not ignore the three-fold difference between Arizona and Alaska.

Longer life through technology,

Thermo

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