Magnetocaloric a zero global warming potential solution

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Well the title of my talk is going to be related to magnetic calorics. And some of the products and R&D that the Building Technologies Program is undertaking. And I titled this a 0 GWP solution. Where for those that are familiar global, warming potential. And I think in its been timely because GWP has been in the news 20 countries, 200 over close to 200 countries came together in agreement part of the Montreal Protocol about reducing HFCs and to enable the half a degree you know for climate change-related to like Sam Rashkin talked about.

And refridgerants are an important part so before i go, I brought a little magnet as one of my props. Before we get into the magnetic calorics debate or talke about the challenges and opportunities that this technology has to offer, first we want to frame you know what’s going on. So what are we doing, in the Building Technologies Program at least in my area that I manage a portfolio related to HVAC water heating appliance we’re trying to create a paradigm shift. And if you look at my portfolio we also take very similar to Amir we take a two-prong approach. One of the promises we work on technologies that are near term but we also work on some of the technologies that are game changers. And some of these technologies are the ones that are the in-state. One of the things that you probably read if you read some of those news articles related to the Montreal protocol and the changes they always talked about low. But they’re not nobody ever talked about zero. And that’s the main objective that we’re trying to enable a paradigm shift. We’re trying to go after and develop the technologies that don’t work about global warming potential of a hundred or two hundred or like in the thousands of GWP that the current refrigerants have we’re trying to go to zero. And that’s an important part to realize and these investment these technologies are not just going to happen overnight you know in the building technology like to take a long-term aspect you see what are the products what are the technologies that are actually going to be game changers and these requires some initial investments.

When we started going down this road and then I’m only picking talking about one of the calorics and i’ll talk about some of the other ones well as one example. But when you look at it you look at the problems you look at the big energy savings opportunity and one of the big things to realize is worldwide power consumption for air-conditioning alone is forecast to search 33 fold bite 2100 as developing worlds incomes rise and urbanization advances. They shouldn’t be doing what we did. How we got here today is not acceptable. You know it’s like Sam Rashkin you know talked about as being good stewarders being able to come up with the next generation. They can’t use the same methods that we used so there are some new opportunities new technologies that can change things. And I talked a little bit about the Montreal Protocol but in 2014 the United States Canada Mexico proposed an amendment to Montreal Protocol and actually before I submitted the slides this weekend is when they actually got together and committed to some major changes to that and adopted and it’s really going to make a big impact. But you know to keep in perspective this is a global solution. It’s not just the U.S. problem is a global solution that we’re talking about. When you look at the U.S. the U.S. historically has been a global leader in HVAC technologies. We have exported our technologies. So it’s in our DNA to come up with the next generation of technologies. And HVAC phase out is more technically challenging than prior refrigerant transitions we have gone through several change out phase down so you want to go completed in the past but in the past it was a little bit easier. And in the past there were always solutions that were there for the taking.

You know people knew Oh we’ll go there. And these solutions had certain characteristics that they made them acceptable they’re very similar. They didn’t have any issues toxicity was not a problem. Flammability wasn’t an issue but you look at it today and it’s not an absolute ban of HFCs but it’s a phase down. And one of the challenges was this phase down is the options the options are requires some R&D. So the world the near-term technologies the ones that are readily available the ones that we are very much used to that based on refrigerants. And i’ll talk about refrigerants later on my talk is that these refrigerants that are readily available have some shortcomings. But if you look want to take a step back and you, how did we get here? In the early days you know we didn’t care we didn’t know much, we looked at refrigerants you know the first generation what worked. You know they were great we use them second-generation while some safety issues came up so we got there. And then the whole issue when we got close to the HFCs, you know ozone depletion came in to the picture. We were all worried about the ozone and that was a major part. But now we’re in the 4th generation the low GWP and in reality i think there’s going to be a fifth-generation, the 0. GWP solutions. And each time you start screening at more criteria more filters and you know becomes more challenging because now there are fewer refrigerants to choose from. And earlier on in the department’s history we played an active role in developing some of these refrigerants for some appliances and refrigerators. And early on in my career at DOE we funded a study at NIST the actually closed the book on a study on refrigerants themselves. They showed what’s possibly out there. It didn’t take into consideration mixtures and blends but a lot of people that were holding out and hope they’ll be a magic bullet silver bullet that was going to solve everything you know this magical refrigerant that was going to come out of nowhere and people would be able to solve our problems, low and behold it doesn’t exist. So now we’re in a phase that we can move on march forward knowing that there aren’t any you refrigerant training you compounds there may be blends where you just like cooking you mix things together to get a lot of new things.

The refrigerant world you know it’s very limited. And if you look at it these are currently some examples. What are we using today well for refrigerators 134a is being used, window air conditioners in some central a/c units very common. 410a common refrigerants and you can see these common resurgence global warming potential is very high in the thousands. That means that you know compared to co2 that comes out you know the magnitude that being one as a relative from a global warming perspective you know they all have high multipliers they. Also have very long life. That means when they get released into the atmosphere they stick around a very long time so it isn’t like in the old days that you know in the past when humans made pieces of equipment out of wood you know whether will degraded it and the wood would disappear. Some of these refrigerants they get vent out into the atmosphere and they stick around a long time. That’s what gave us our first indication that the ozone layer was disappearing holes started.

Scientists was informing us that these holes were appearing and part of it was that those refrigerants that were being released had a negative impact on the world. And they were just sticking around. There were a reason why they were so inert and so safe for us but they didn’t decompose into its basic elements. And if you look at potential future GWP you know refrigerants low flat you know if you look at these candidate blends or different refrigerants you’ll see one thing that a lot of them have. Yes they are going lower from a global warming potential but you see that they have some trade-offs in the major trade-offs are a lot of these are that they are flammable. So they’re a price to pay and a lot of these also would entail a lot of R&D to be dropped in replacements so they’re not the easiest to implement. And their safety like I said the flammability so there are a wide range of options and these options are being pursued at this time to make them in the realm the manufacturers will feel comfortable commercializing them. And here’s one of the slides that I usually tell, talk to people when I explain to them what is a heat pump on air conditioner, because a lot of people look at it and they think it’s like magic that’s occurring. And it’s not magic. You know one of the things you realize is that when we develop these next generation of equipment be it refrigerant based or non refrigerant they sort of have some basic components. And this is where one of my props comes in. I think most of you have made be around your house you may have a little can to clean your keyboard and very few people know that this is actually a refrigerant. This is actually R152a it is a low GWP refrigerant. There actually was developed for the automotive industry and the automotive industry did not utilize it and the main reason they didn’t utilize it was flammability. So that sort of moved them away and now where is it? They’re in shelves everywhere. And one of the things to realize and I always use this as an example to see how the vapour compression cycle works is I think most people have used it and if you realize it just like if you have here it actually is extracting heat from the bottom it’s getting cold. This is very similar to what is happening in in a heat pump or of the vapour compression system. You extract the heat from the environment you have a liquid something that’s where the vapour compression comes in. You have a liquid that’s expanding to a gas and when it attracts the heat from the environment you know provides the cooling. In a closed loop system that you have a cycle like in a heat pump or an air conditioner you bring it back from that gas phase and use a compressor to get it back into a liquid state. That requires energy. One of the things that we talk about is we’re not EPA we’re the Department of Energy so we’re an energy efficiency first organization so whatever we do it also has to be energy-efficient to begin with. So you have the compressor you get it back to a liquid similar to this can you release it. You know that provides the cooling or the extraction.

A heat pump works the same way accept the condenser and evaporators get switched around so you move the heat like for cooling, you you take the heat that’s inside of a building and you move it outside. For heating you bring the heat that’s outside and you bring it inside so it’s all about moving heat around not actually burning fuel or using electricity or something. The energy contained in that fuel itself. So the other thing is going to tell people is if you have one of these things there is a lower solution can always use handy brush to clean your keyboard. This does this is a 0 GWP solution so i highly recommend it. So now we go into caloric materials. Caloric materials are a class of materials that instead of having a refrigerant their solid state. And one of the things that makes them very worth while pursuing with them is that when you have a vapour compression system you have a vapor and that vapor is very hard to keep inside the system itself it due to how operational needs human error maintenance the refrigerant over time escapes. And that’s where a lot of the Montreal Protocol issues comes It’s in with these direct impacts to the environment in the climate itself. These units you know these materials that are solid state base have the advantage of not being in a vapor themselves that can escape. When these vapors escape these refrigerants they make that are a large impact on our climate themselves. Caloric based systems coefficient of performance scale proportional to the magnitude of the caloric effect and inversely proportional to the strength of the driving force. And i’ll go into greater detail of the meaning to that but all these materials have a driving force. These caloric materials and have the benefits of caloric materials and this is very important is scalable.

Right now just like you when you drive a car you know the automotive companies or be it or even the HVC manufacturers they developed compressors and those compressors come in discrete sizes just like you buy a car there’s only certain number of engines and manufacturer will put in resources to develop and it takes very intensive a lot of resources. These materials that are solid state have the potential to be scalable so you can do a small amount and then scale it up and tailor the right capacity to the right load. Right now most of the time we sized pieces of equipment and operate in their size for full load capacity. When you may only operate a few hours or minutes out of the year. Then you have two partial load most of the time they’re operating at very smaller capacities so you they’re incredibly oversized so they’re not very efficient and their performance degrades over time. When something is based on the material properties themselves they degrade in different ways and potentially they have the characteristics of being able to maintain performance over time. Caloric effects are maximized when a material switched from a disordered into an order of state or from one order to state to another. I’ll have a slide resulting talking about that and the resulting effects may be enhanced with first order effects. The simplest. And i’m going to be talking about one of the magnetic one of the caloric effects magnetics the ones that have a magnet to talk about. So the caloric it’s materials one of the things to realize is in reality they’re just three basic fields that we work with. There are opportunities to mix mechanical with the electric and magneticd but in reality they’re just three major ones. One with an electric field and i won’t go into detail but the electric field means that instead of using a magnet you vary that electric field. There are some advantages to some of these technologies and we are pursuing them.

Magnetic caloric we’re the ones that I’m going to be talking about in a little bit greater detail those are the ones you have a magnetic field and you very that field most often that means moving a magnet or moving the magnet around, in and out of the magnetic field to give you this oscillation. Mechanical, and that in itself results in a change in temperature thermal and all three of these can be used together or individually are but those are the caloric effects or the caloric materials and we’re pursuing all three of them. And the main reason that I brought up you know magnetic caloric is that it’s one of the more mature ones of the caloric ones. It probably has like a 30-20 year head start over the other calorics talked about earlier. It’s the most mature it is an emerging technology one of the things is that it’s in mid-stage of R&D that means that they’re prototypes that we have built. They may not be fully vetted yet for commercialization but one can see that within the next three to five years there should be some products being sold. There’s talk about one company in France cool tech with a refrigerator that they’re supposedly is for sale doesn’t hasn’t hit the market yet but you know just gives you an indication that people are talking about commercializing so this is not science fiction.

You know prototypes have been built, manufacturers are looking at potentially producing these units at volumes and but you know they’re still a lot of R&D left to be made to make them to a level that consumers feel comfortable with them. You may be wondering you know how does this caloric magnetic caloric work you know what is going on that makes it worthwhile. You know what’s actually causing this delta T. And the real issue is you have a material like gallimidum usually considered the baseline material and you have this material on it and you can see that you have this material and the electron spins are randomly spread out through this material. Then you put a magnet over this material by passing it and then they aligned so that in itself this is like when you get to the B they like themselves. But at the alignment there’s also a temperature the temperature goes up. Then you use a working fluid like a liquid or something to remove that heat this extra heat that came in. And then you remove the magnet once you remove the heat because right now it’s a little bit above they become the scattered again but this time the temperature will go lower than it was before it started. And that’s where the cooling effect comes in. And then you just repeat the cycle by putting the magnet again heats up you remove that heat that a plus up and you can stage this. And by staging by putting a a bed of materials because different materials will have different characteristics you can actually go down as low as zero or even lower below zero and you keep doing this over and over and that’s how you have a magnetic caloric cycle. In the building technologies program initially and i’m just going to talk about two projects is we first looked at magnetic alerts for refrigerators.

During the recovery act we funded a project with General Electric and that project actually was just focusing on the material discovery and usually coming up with these materials that could actually be used and GE characterized enough material discovery and identify certain materials that later on we were able to have a follow-up project with Oak Ridge National Lab that we actually had one of their prototypes come into the building technologies and we invited all of the EERE to come and see how they were able to cool down a soda can. They were able to demonstrate that yes we can build a prototype but there’s still a lot of work to be done not so much in the materials from the system integration. We’ve gotten very good at vapor compression. Vapor compression has been around for a hundred years. We haven’t fully maximized or optimize what the ideal physical configuration is going to be for a refrigerator for the regenerator. So we’re in the right now in the components the materials that are identified earlier maybe not be the ideal but they’re good enough. And when GE was visited the building technologies program they stated that you know they believe the magnetic caloric as being a technology of the future. They believe that the technology can easily meet our current energy efficiency standards and is the cheapest solution for the future to be able to meet future regulatory hurdles related to meeting appliance standards requirements. So you know one of the things is yes we want to transition to these zero low GWP solutions but also industry fully understands its potential because there are costs associating. Vapor-compression were sort of plateauing from an efficiency point of view but also for an environmental liability point of view. And these caloric materials open up the possibility to go to the next generation. And the next project you know we talked about refrigerators are actually will give you a boost over vapor-compression but for a window air conditioner we know that the US needs better air conditioners and maybe magnetical caloric, it’s not an ideal to scale up to full-size home units but window units for the developing world in other countries may be a viable solution.

One of the things that the innovation that came in from this project it isn’t so much the material play as the system. Most of the time when you’re passing the magnet how you remove the heat becomes the real challenge to make a full working system. How do you remove the heat making it work. One of the advantages that vapor compression had is that you had not co-located you had a heat exchanger something that will extract the heat inside home and another component like i said earlier a condenser or an evaporator depending if it’s a heat pump on air conditioner outside your home. An outside unit and those two are not physically located but now you have a magnetic caloric material or any of the calorics and you’re applying to feel and all these thermal exchanges are a point source. They’re happening here when in reality you want something to happen here and in here. So designing a system and coming up with configurations how you would make this system work they’re not trivial and that’s where Oak Ridge’s innovation came in by not having some of the additional plumbing for these thermal exchange by having metal rods and even though they have moved away from some of the principles of using rods but physically coming up with physical configurations that actually can enable the use of these caloric materials in designs and concepts that we are just starting to pursue. And you know magnetical caloric probably you don’t hear that much or any of the calorics in the news but potentially they are the next generation of solutions. The solutions that are the zero not the low, but go beyond to something that would be zero and then at the end would just be focusing on energy efficiency only and removing the environmental consequences of the direct emissions of these refrigerants. And if you want to read about any of our other sophisticated projects including some of the other calorics you can go to the building technologies website in the HVC water heating appliance we have project write ups for every single project so you can have additional information and peer-review presentations and you can always email me and i’ll be able to guide you through that knowledge and see where that information can be found. That’s it thank you.

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