Webinar System Level Thermal Solutions for Military Grade Technologies

Show video

hello everybody and welcome to advanced cooling  technology's november webinar we'll be covering   system-level thermal solutions for military-grade  technologies. Our speakers today are Matt Keller   and Devin Pelicone. Matt is the general manager of our york Pennsylvania location where he oversees   design production and service operations armed with over 17 years of engineering experience. Matt provides invaluable expertise in ensuring ACT's customers get the best thermal solutions   and technical service possible. Devin is the lead engineer of ACT's industrial products group at our Lancaster Pennsylvania location.  he has over 10 years of experience designing   and building both passive and active two-phase  cooling systems for a wide range of applications   including high performance computing and power  electronics cooling before we get started i want   to let everyone know that there will be a live  question and answer portion at the conclusion of   today's presentation if you have any questions  feel free to submit them through the present   throughout the presentation by using the  question function on the dashboard matt and   devin will be will be answering as many as time  allows we'll follow up with an email for anyone   whose questions are not answered live with all  that said i'll turn things over to our speakers thanks kevin good afternoon everyone thank you  for joining our webinar today tell you a little   bit about advanced cooling technologies we  are a thermal management company located   in lancaster pennsylvania as our headquarters  and we also have a branch in york pennsylvania   we were founded in 2003 and we now have  over 200 employees at both locations   we have approximately 140 000 square feet  of facility space and growing every year   and we have an iso 9001 and as9100 quality  management system we've won a number of   awards through the military and aerospace  product innovation awards for the different   technologies we've developed over the years we  also work exclusively work extensively in the   small business innovation research grant so we won  a number of tibbetts awards for that work and we   have numerous patents and scientific publications  related to thermal management technologies today we're going to be talking to you about  some of our system level cooling technologies   particularly environmental control units  or ecu's glycol coolers and chillers some   of our pump toothpaste or ptp cooling systems as  well as phase change materials pcm and we'll end   with a little bit of discussion about some of  our electronic systems system controls um and   packaging capabilities and then a little bit  more about our testing and extra capabilities   at the end and like kevin mentioned we'll be  ending with some question and answer session   to answer any questions you may have i'll turn  it over to matt keller to start things off thanks devin when we talk about system level  thermal solutions we're referring to equipment and   accessories utilized to reject the heat generator  by system components to the exterior environment   that's usually the ambient condition ambient design conditions can be  anywhere from negative 50 to 140   fahrenheit and zero to ten thousand feet  elevations for terrestrial systems in some   cases there may be a chill water infrastructure  which would be the exterior environment we reject   would reject heat too for example shipboard  chill water or a facility chill water system so the first thing we need to understand is  the design criteria what are the heat sources   electronics are going to be a big one  in pretty much every system these days   and they're going to be sensible heat that  may be a very continuous load or it could be   transient in the case of directed energy systems  occupants may be present in the system and they   provide both sensible and latent  heat loads that need to be addressed   the envelope of the system allows conduction  from outside temperatures to inside as well as   additional thermal loads that come through due to  solar radiation on the exterior skin of a system   outdoor air may also be a load in the  system if we're going to be providing   fresh air for pressurization and making  sure any leaks in the system leak out   as well as ventilation for the occupants once we know what the loads in the system are  we also have to understand what we're trying   to maintain in the system so what's  what are the acceptable conditions   for electronics that's usually an entering  air temperature to the electronics   um with occupants it's more of a average space  temperature that's being controlled um 60 to 80   degrees fahrenheit is kind of a reasonable  range for that relative humidity below 60   is also usually required traditionally we don't  get into adding humidity because of the logistical   issues of providing a water source and maintaining  a water source to keep the humidity levels up so one of the solutions we offer are environmental  control units an ecu as we call them is basically   an air conditioner built for military environments  they provide conditioned air to an enclosed space   uh they can be mounted uh to hard wall shelters  or connected to soft wall shelters or hard wall   shelters uh via flex flexible ducts so you see  some photos here um there's a five ton ecu on   the back of a trailer um behind a humvee uh we've  got systems that are in the middle um that's again   a five time possibly an aid time hooked up to a  software shelter um there's a radar hub cooling   unit in the upper right as well as a dual vertical  system that's hard mounted to a hard wall shelter design considerations for ecu's um actually okay uh additionally ecu's are a good  way to introduce outdoor air to a system   that out to air can be pulled in and mixed  with the return air so it can be conditioned   prior to being introduced to the space also we  can do 100 outdoor air in the case of flight   cooling so the picture bottom left shows  100 outdoor air unit that maintains   temperature of electronics while sitting on the  tarmac which is the systems on board that uav   aren't suitable to maintain temperatures when  you're sitting at up to 160 degree f conditions ecu design considerations air systems are a great  for going redundant system either if that's for   additional capacity part load condition kind  of capacity or complete redundancy with air   systems you can use plenums and ducts backdraft  dampers to kind of manage those connections   and redundant systems are great for  unmanned or mission critical systems   capacity ratings for ecu's is determined by the  ambient condition so if the ambient condition is   higher in temperature that will decrease  the capacity as well as the return air   conditions so temperature humidity airflow rate  basically the more energy you bring back to the   unit the more cooling it can do so when you  when you think you know what load you need   understanding return conditions understanding  the ambient conditions will affect   the rating of that equipment and  when you're evaluating solutions   you really want to understand what the capacity  you're being told is is based on somebody may call   something a five ton unit that we would call a  three ton unit depending on the rating conditions uh airflow pattern in the  space is also very important   these drawings kind of show a couple  different ways the airflow could be managed   on the left you have short cycling so you have  air coming out of the ceiling goes right into   a return and occupant and the loads don't see  all of that air on the other hand the far right   is really how you'd want to do a data center  or electronics type environment where you're   providing cool air to an occupied space that's  then available for the electronics and the heat   is then directed directly back to the unit because  as we just said the hotter the air to the unit the   more capacity you get out of that unit so um  the way a unit's connected to a space the way   the air is moved through the space is critical  and making sure that the defined requirements um   are actually provided to the equipment the  equipment can actually meet the design into that another solution that we have experience  with are glycol coolers and chillers   glycol coolers we refer to here as liquid to  air systems um basically provide cooling liquid   at some temperature above ambient  so these are a coil a fan a pump   and basically a radiator where we can provide  electronics with a a cooler than you know their   we're providing liquid cool enough to pull the  heat away from them and keep them happy but we're   not providing coolant that's below the ambient  temperatures alternatively we can do chillers   chillers provide cooling liquid at a fixed supply  temperature so we can provide let's say 45 degree   fahrenheit glycol even when ambient temperatures  are much higher than that so that is uh good for   electronics to require low ambient temperature  cooling as well as fixed temperature cooling um   so there may be something that's calibrated  uh needs to have a constant temperature uh design considerations for glycol coolers and  chillers um you know when you when you go to a   glycol system you have to make sure that the  components in the system are designed for that   right so you need heat sinks that accept  glycol electronic equipment designed for   a chilled fluid piping and fittings that  don't leak are obviously important if   the system is modular quick disconnects  are needed so that you can disconnect um   system components either for maintenance or  replacement or if you're going to strike a system   for relocation weight also needs  to be considered when you're adding   fluid you know an air system obviously  there's no additional weight penalty   to the volume of the duct system uh but with a  glycol system any any storage any piping would be   filled with glycol and therefore that weight would  be a consideration in addition glycol storage   tanks or pcms phase change materials can be used  for thermal storage this makes a lot of sense when   you have a system that doesn't have a continuous  load you can downsize the system to deal with   the average load and use the storage volume  to address intermittent loads this is great   when you're looking at directed energy weapons  where the peak load may only be present for a   few minutes out of an hour devin will tell you a  little bit about a previous application like this thanks matt this is a case study for a direct  energy weapon combined vapor compression and   chiller system so this is using the phase change  material so this is the solid to liquid energy   storage mechanisms this would be latent energy  storage as compared to using a sensible which   would be just a giant liquid tank this is for  a direct energy weapon mounted on the back of a   humvee as seen in the bottom left there and really  what we're showing is how tightly packaged a   system like this can be if you needed to size the  vapor compression system for the peak load of the   laser in this particular application the entire  system would have been twice this size so we were   able to significantly reduce the size of the vapor  compression system by coupling it with a energy   storage media like pcm and then also including the  chiller system inside of this box um this entire   package you can see mounted on the left-hand side  of the humvee here includes all the pumps all the   fans all the electronics all the paper compression  components all of the sun within one package so it   makes a very complete thermal management solution  for highly transient uh pulsed energy loads next we're going to switch gears a little bit  here and talk about a different type of cooling   technology this is similar to what matt was  describing as our glycol coolers except this   is what we call pump toothpaste cooling so it's  an above ambient liquid cooling solution but in   this case we're allowing the working fluid to boil  or change from liquid to vapor as it flows across   the heated components so it includes a pump it  includes a condenser an evaporator and a reservoir   a lot of the same components that a glycol system  would have but the working fluids are typically   refrigerants or dielectric fluids that boil at a  relatively low temperature and pressure they are   hermetically sealed systems so we can allow that  boiling temperature to fluctuate depending on what   pressure we impart on the system which is really a  function of how we cool the system so they can be   paired with some of the chiller solutions that  matt was mentioning earlier so that we can do   below ambient cooling but the system by itself is  not capable of doing any refrigeration we really   need that refrigeration cycle coupled to the  condenser in order to get below ambient conditions   so some of the benefits of two phase over a  glycol chiller most of them revolve around energy   efficiency so because we're using the weight and  heat of the working fluid instead of the sensible   heat like we would in glycol chillers or coolers  we're able to use a significantly lower flow rate   of the fluid orders of magnitude lower in fact  and so that allows us to really shrink down the   pump that's required for the system for packaging  reasons it allows us to spin the pump at lower   speeds and it allows the system to run with our  energy consumption so that's a big benefit another   benefit is that because again we're changing  phases this all happens at a constant temperature   as you boil the fluid and move from a sub-cooled  liquid to a saturated liquid and eventually vapor   that all happens along a constant temperature one  and so as you're flowing across the evaporator the   components mounted to that evaporator see a  constant temperature which is not the case   in a glycol cooler where the fluid's heating up  as it's flowing from one side to the other so if   you have multiple components i'll mount it to the  same evaporator they can all be with maintained   within about five degrees c of each other  and then we can maintain 10 degrees c   uh temperature difference across the entire loop  so highly energy efficient uh method of cooling there's a lot of considerations  that are different from a glycol   system or a sensible cooling system to be  discussed when talking about pump two phase   the first is the heat absorption devices we call  them evaporators because we're changing phase   and these are very similar to the evaporators you  may see in a chiller or vapor compression system   they could be conduction based meaning you mount  your heat generating components directly to those   parts or they could be air to refrigerant heat  exchangers much like an evaporator coil would be   in a standard air conditioning system or it could  be some combination of those and there can be many   different evaporators all within a given system  one challenge that comes up with two-phase cooling   when you have multiple parallel evaporators like  we're showing in the bottom right image here   is that you have some flow balancing issues  to deal with if you have one evaporator that's   dissipating more energy than the other then  the fluid will boil more in that evaporator   compared to others it'll create more pressure  drop and then you have this sort of unbalanced   pressure balance in your manifold that you need  to deal with the way we deal with that is we add   flow restrictors to the system so that we can  run as many parallel evaporators as necessary   all at different loads or no load at all and be  able to provide constant flow rate to all of them   another consideration that's unique  to two-phase cooling is refrigerant   or working fluid selection in a pump two-phase  system it's a little counter-intuitive but the   pressure drop across the loop actually um results  in a thermal resistance change as we drive around   the loop the pressure decreases and then the  temperature of that fluid also decreases and so   that reduces the amount of temperature gradient  we have to get that energy out of the fluid and   into the air so that combats the uh the thermal  resistance of the system requires us to have   bigger condensers more airflow things like that  so what we're really trying to do is minimize the   pressure gradients around our loop in a two phase  system in the top right we're showing an example   comparing r134a to r245fa they're two different  vapor pressure refrigerants that could be used in   a pump two phase system r134a is significantly  higher in vapor pressure so at 50 degrees c   operating point the resulting pressure drop of 10  psi around a loop only has a one or two degree c   temperature impact but if we were using a  fluid like r245fa at that same temperature   a 10 psi pressure difference across an evaporator  could have up to an eight or nine degrees c impact   on our system performance so picking the right  working fluid for the right application um in   the right conditions is really critical and it's  something we take a lot of care with when we're   designing these pump tube based systems another  uh instance that we need to keep uh in mind with   these systems is that the refrigerants are  ozone depleting a lot of them there are new   low global ring potential replacements for a  lot of fluids we're showing some of them here   if that is of concern for your system we have  a number of fluids in our repertoire that   have either zero or very low global warming  potential that we can use the last note is   uh related to pumps which comes up a lot when  we're talking about pump two phase systems uh   refrigerants tend to be very low viscosity fluids  and we're operating very close to the saturation   point of those fluids so pump cavitation and pump  performance is a real concern we try to select   pumps that have very minimal net positive suction  head and psh and we're usually using pumps that   have positive displacement to make sure that they  can accommodate low viscosity fluids it's always a   consideration to make sure we're getting the right  sub cooling in the loop so pump two phase systems   really are a system level design you can't design  one component without consideration for the rest some applications of uh pump two phase a lot of  them are electronics related what we're showing uh   in the larger image on the right is actually what  we would call a current distribution unit or cdu   for a very large data center application  this is a 200 plus kilowatt um condensing   unit and in this case it happens to be a liquid  cooled condenser so we're using facility water   or whatever water source is available possibly  from a chiller to cool the refrigerant down to   the saturation temperature that we want to send  off to the servers to do our cooling right below   the condenser which is that large orange rectangle  at the top is a reservoir because we're changing   phases from liquid to vapor there's a volume  change that needs to be accommodated and so we   need some volume in the system to account for that  difference in density and then all the way at the   bottom are our pumps they tend to be n plus one  redundant depending on the system we're working on   uh positive displacement pumps distributing  that liquid to all of the many servers   that this system serviced in this case i believe  it was servicing up to 40 individual server   blades all from one central pumping so that's  what i mean when i say we can handle multiple   parallel evaporators as long as it's designed  appropriately some other applications on the   bottom there are utilizing either air or liquid  as their condenser in the middle is a large uh   30 kilowatt coolant distribution unit with a  sort of uh residential air conditioner style   condenser coil that's u-shaped that we're using to  dissipate the energy to the ambient air so these   things come in all different shapes and sizes and  can be suited for any application and there's also   the ability to combine pumped two phase with  vapor compression because they're often using   the same refrigerants to be able to do some sort  of hybrid energy efficiency refrigeration cycle   so you can use eco mode and pump the  refrigerant to the evaporator when   the ambient conditions allow for it and when the  ambient gets too hot you turn your compressor on   to be able to do sub ambient cooling to keep  your system at optimal temperature all year we talked about phase change materials a little  bit in the direct energy weapon application but   there's other applications for this they can  be used to supplement air or liquid systems   um as well as electronics they're really  we would consider these thermal batteries   or thermal capacitors so any system  that has a transient thermal load   can benefit from having a phase change material  to damp out the peaks and valleys of that load   in a glycol system the pcm like we talked about  can help reduce the swap of the system to damp   out those pulse loads and minimize the size of the  rest of your components a key thing when utilizing   phase change materials is that they're often  fairly poor thermal conductors on their own   and so they require quite an  infrastructure of thermal pads   in order to distribute the heat into them evenly  and utilize all the material we're showing an   example of something like that in the bottom  left where we're using sort of a folded thin   structure in order to distribute the heat evenly  throughout all the phase change material so that   you're really utilizing all that extra mass  you're adding to the system if you don't have   something like this in place then you wind  up with clumps of solid and liquid material   in there and you're really not getting the  weight optimization that you're looking for so phase change materials come in all  different temperature ranges a big benefit   here is that again this solid to liquid phase  transition happens at a constant temperature   and so while you're absorbing all that energy  of your transient load you're not increasing the   system's temperature or components temperature  we're showing that schematically on the plot on   the right here you increase in temperature all the  way up to the melt point of that material and then   you flat line while you absorb all the latent heat  and then once you have melted all the material   the temperature rises again and you're back to  sensible heating now in liquid phase instead of   solid phase but that melt zone is really where a  lot of the energy is absorbed and where you get   the biggest bang for your buck out of these  materials schematically at the bottom we're   showing another example of this sort of pulsed  energy system where the peak load is shown by the   red bars and this is the energy that would need  to be dissipated by a vapor compression system   or an equivalent chiller if you didn't have  some sort of thermal capacitor in the system   the blue lines is showing the damped out load  and you can see very clearly that having a   load shaped thermal profile reduces significantly  the load on the overall system and so all those   components get smaller they get more energy  efficient and your system becomes more optimized   the last thing to note about phase change  materials here is that they come in almost every   degree c increment from negative 60 degrees c up  to positive 400 and almost everything in between   those are not all the same type of material so  materials compatibility is a real consideration   here but there's lots of options for for how  you implement these materials into your system so i'll hand it back to matt to talk a  little about our controls and electronics um so when we put together controls package one  of the things we have to start with is what are   we trying to control for air systems if you're  doing an occupied space you might do return air   might kind of function like a house residential  style system where you're basically looking at   the air coming back and once it gets too warm  you start to cool once you get too cold you turn   it off so you can cycle on and off we also have  modulating systems either through the use of a   digital compressor or an epr valve and that gives  you a tighter temperature control um supply air or   supply glycol control can be used for electronics  and there you really do want to have a managed   flow path so if you know that the air you  deliver to the space or the liquid you deliver to   the system will go directly to the loads  that that temperature can be increased   uh which optimizes performance of the system  when you have poor distribution that's when   you have to supply colder air because it'll get  mixed before the electronics actually see it   sometimes there's a critical location  in the system so we might have a temp   sensor directly at a piece of equipment  and you might control the whole system   just to keep that one piece of equipment humidity  again can be a control point we may use hot gas   reheat or electric reheat to over cool the  air and reheat the air to bring out moisture power draw and inrush events are also something  to consider with the control strategy if   if there's not vfds in the system  then you really don't want to bring   on a big load at a at a time when a  brown out to the power system could   cause issues to other system components so  we have systems that will operate continuous   compressor and that's not energy efficient but  that is good to keep the power system stable   uh if you're doing some sort of scanning or radar  activity where you can't deal with reduced voltage fan and pump speed modulation also may be used  in the system um we do have systems that will   ramp down the airflow to the shelter when the  cooling load is not at its greatest a lot of   these shelters are not very large they pack a  lot of cooling load into a small space and so   it can almost be a wind tunnel in there at times  so anytime you're not in that worst case condition   to back off airflow does make the interior  environment a little nicer we do have different   types of controls we use here electromechanical  controls um digital digital temperature controls   as well as plc where we can basically come up with  any custom control configuration that's required   uh local control interfaces could be as simple  as an on off switch or red to blue dial uh to a   touch screen that allows you to change set points  by tenths of a degree remote connectivity is also   something that we can provide uh can we can  do ethernet based communication modbus snmp   tcp ip as examples and use discrete  connectors and have analog signals   to report temperature discrete signals  to report specific conditions or faults so uh to summarize kind of our  capabilities um you know we want to be   involved in the project as soon as possible  we want to help steer the system level design   to make sure that all the components can be  optimized so really getting involved at the   requirements definition stage is ideal but we go  through the kind of normal military design cycle   with pdr and cdr uh cdr phase critical design  phase uh we'll work on mechanical packaging for   the environmental requirements we're very  familiar with mill standard 810 testing   for shock and vibe um all kinds of environmentals  blowing uh sand and dust snow wind salt fog   um we've gone through lots of emi testing that  really is something that is unique every time we   do a design we always recommend if there are  strict emi rfi requirements that we do those   by test we'll also do reliability analyses at  the cdr phase then you know we will procure the   materials based on any flow down requirements uh  and get into manufacturing we do test 100 of the   equipment we make for thermal performance  at increased ambience we do that in house   and we will go outside for qualification type  testing based on the environmental requirements   system support is then offered with o m  manuals spare parts and replacement procedures   and we deal with component obsolescence  as we help to support these systems for   up to 15 years 20 years we offer training  services and support and repair and reset uh i hope everyone's been asking questions as  they have been going here but i think we have a   poll that we're ready to introduce yeah thanks man  we're going to take a couple minutes here to uh   to send out a poll survey here you'll see it pop  up on your screen please feel free to answer that   and if you have any questions relating to  our talk or really anything and put them   into the chat box here and matt and i will be  answering your questions live in a couple minutes thank you matt and devon for sharing this  information and thank you to everybody who   participated in our poll this time we're going to  transition to the question and answer portion and   thank you again to everybody who's made questions  throughout the throughout the presentation and   feel free to continue asking questions and we'll  get to as many as we can so our first question   here uh how do you recommend determining  the actual electronic fluids in the system well that's a great question you do want to   consult any manufacturer's data first they're  going to be the experts on their equipment   but anytime you can run a system and collect power  draw it'll give you a good idea what's happening   you don't want to just add up worst case loads  and assume they all happen at once all the time   that's a sure way to oversize your system and  that causes all kinds of problems with control   so we definitely try to guard against that yeah  it's also important if it's an electrical cabinet   to consider the loads from the ambient this gets  neglected sometimes when we're sizing components   like enclosure coolers and things like that it's  important to consider the the solar loading on   the cabinet any natural convection loadings if  you're in a hot environment the electrical loads   are definitely one of the main components but  those things can't be neglected either so make   sure you're considering all the potential loads  like matt went over in the slides earlier all the   loads that could be in your system to make sure  you're really getting a complete thermal solution how do you deal with low thermal conductivity of  gcm resulting in a relatively long melting time   i think you should do that we talked about this a  little bit in the uh in the talk so pcm materials   most of them are are pretty terrible thermal  conductors and so what you're really trying to do   is to short-circuit the pcm as much as possible  thermally and so that typically requires having   some enhanced surface area inside of the pcm  material you want to embed high surface area   materials with phase change material try and  minimize the conduction path as much as possible   that'll give you the best result in terms of  how much pcm you need in your system and how   efficiently it reacts over time it'll also  minimize your your melt times if you have to   conduct through a poor thermal interface like a  liquid layer of pcm before you get to the solid   that's only going to slow things down and it's  really going to increase the temperature gradients   in your system so it's really a system level  solution some people think that phase change   materials are as easy as dumping some wax in a  box and that's um that's not quite going to get   you there it's really a highly engineered system  so we make sure we take all that into account   do you ever work with sterling cycle coolers the the short answer to that is not really we  have done some cryo cores in our research and   development group so sterling cycle using  cryo cores but most of our refrigeration   systems are the ones matt was describing  where they're vapor compression based um   really the sterling coolers tend to be more  for cryogenic applications and we don't see a   lot of those it's not to say we wouldn't do it  uh we just haven't done done a lot of it today can you talk more about how cooling data  centers um and how to cool data internal   cool there's a lot of ways i'll talk about  the liquid cooling maybe you can talk with   the aircoin yeah um so we did mention that pump  two phase application which was for data center   cooling that's kind of the new wave of handling  these these really high heat load high performance   computing type of data center applications and the  reason pump two phase is really suitable for that   application is that it's capable of absorbing a  lot of energy with a small amount of energy input   so it's above ambient cooling solution so a  cooling tower or some ultimate rejection system   is needed on the roof of your building but at the  server level you're really picking up the most   amount of energy or heat per unit of energy input  into the system using um pump two phase coiling or   some sort of liquid to vapor cooling technique  and so when energy efficiency is really the the   name of the game and data centers that that gets  you where you need to be at the server level   yeah i mean even if you have chill water in the  building you know a lot of people are not going   to feel comfortable putting chill water into this  into the server area so a heat exchanger to a two   phase pumping system one of the benefits of that  refrigerant is if you have a leak it'll it'll leak   as a gas so you're not going to have conductive  liquid all-over electronics if there's a leak so i   know that pump two phase even with the chill water  system is still kind of preferred at the load   and like you said with the continuous  or the constant temperature across the   heatsink it really allows for optimized  equipment um from an air system side   um hot oil cold aisle might be terminology you're  familiar with and this is really about making sure   that the cold air from the crack units or  whatever the air handler is called in the system   is delivered to the inlet of the equipment and  then the hotel would be where the racks blow   everything out so you know one of the things  i've seen in some kind of tactical systems is   you have a hodgepodge of equipment some have  fans in the front pulling in some have fans in   the back pulling in and so now you you don't have  all the equipment even pulling from the same side   so very quickly you can have a piece of equipment  that gets the heat from another piece of equipment   and isn't happy even though you know the air  handler attached to the system is about a quick   capacity there can't get to the electronics you  have trouble so definitely taking into account   the direction of airflow and management  of the airflow for the electronics   is a big thing and our last product coming back  to the energy efficiency part for data centers   that we didn't talk about today is a product  called a wraparound heat pipe heat exchanger   and this is actually incorporated directly into  the air handlers for the crack units and what it's   helping to do is to enhance the dehumidification  of the system so you can do some pre-cooling some   free reheat on the system we also have air-to-air  energy exchange products where you're recycling   that air through the data center and you tend  to be throwing away cold air that's already been   conditioned you can use that energy to pre-cool  the hot air from the outside without needing to   input any more energy into the system and so  it can improve the overall energy efficiency   of your data center even if you're still  using air cooling it could even work with   the liquid cooling systems so that's quite a lot  of technologies for for data center applications what is the max power that can be  removed in two-phase cooling from an asic   by 20 millimeter with exposed dye that's a great question um we have done some asic  cooling it's um i'll i won't talk specifically i   guess to that die but we have developed pump two  phase coin solutions for up to about 300 watts per   centimeter squared um cooling applications it it  depends a lot on the the type of application it   depends on what your maximum temperature can be  and how exotic we get with the evaporator we've   done some true micro channel cooling evaporators  for pump two phase where we can get even higher   heat fluxes it's a little bit r d um if the  question is referring to immersion cooling   so direct cooling of the junction itself we have  a little bit of experience again that's more r d   but you're impinging the refrigerant directly  onto your exposed chip and you can do that   because they're dielectric fluids  and they won't short out your system   the word of caution there is that surface area  tends not to be sufficient when you're doing   immersion cooling you want a lot of surface area  to distribute that heat flux to the fluid or you   start to create vapor bubbles very rapidly  on your surface and then it creates this   sort of critical heat flux situation where you're  impinging liquid onto a vapor bubble and it's not   really hitting your heat source so there's a lot  of considerations there that's a very challenging   problem but we do have experience with very high  heat flux microchip microchip cooling applications what is the realistic duty factor for  heat load from the equipment power draws that's a tough one um you know i know sometimes  uh we like to use like whatever kw is being pulled   into the equipment is the kw of heat we have  to reject obviously theoretically that doesn't   make sense because some meaningful work is  happening um so we tend to use like an 85   percent as a rule of thumb but really it's going  to depend on the application the actual equipment oh it looks like we're having time so as a  reminder if we didn't have time to answer   your question we'll be following up with an email  additionally if you think of any more questions   or if you'd like to schedule a call with our  engineering team to discuss thermal management   needs for your ongoing projects you can send  an email to solutions at 1-act.com thank you  

all again for attending today's webinar and we  hope you'll join us again soon have a great day you

2021-12-01

Show video