Fin Heat Exchangers | Plate Fin Heat Exchangers - Part 1 | Alison
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Module 1: Fin Heat Exchangers

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Plate Fin Heat Exchangers - Part 1

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Plate Fin Heat Exchangers - Part 1
 
Welcome to this lecture, the topic that will be discussed today is about the plate fin type heat exchangers.  This plate fin type heat exchanger that is completely a new type of exchanger we have not discussed in the previous lectures. As you will be able to understand from the I mean following slides so before going into the details about the play thing it is nearly does look where it belongs to in the classification of the heat exchangers so according to the classification and classification according to the construction you will find that the concept class of exchange of where we had the extended surface heat transfer there was a class where we had heat exchangers with extended heat transfer surfaces and one of the derivative of this extended surface heat transfer is a place in time and that’s what we call it will type it in here so if we look into the other classification but we will be able to find where it exactly it is longer you will find that there is a classification based on the surface compactness and if you look into that classification we will find that there is the class of exchanger which is compact and the compactness is defined by a perimeter beta which is defined asbetween the compactness unknown compactness is 700 m squared per metre cube this classification has been recommended by Bishop and his classification of heat exchangers in the critics there’s some hydraulic fundamental and designed that is the book edited by a skunk and it also will be fine this moment of calling the heat action yet as compact if the compactness factor-beta is more than 700 mf4mf you so this particular main type of heat exchangers belongs to that category that it will be more than 400 m squared + 700 metre per metre cube particularly the sell guns to freight heat exchanger and in this region compactness define by 700 metre square per metre cubethen we have and then 30 now this app but that’s what is the beta factor that’s what we are trying to defined and then we also have the log mean temperature difference now this parameter the amount of heat that we can the heat load party will it delete it is basically we can find that if the function of John and Fay and also the you so if we have a very high little early we can expect a small value of Delta fee which will be anyway if cube identity is constant is remaining constant then for a given cube identity we have you fixed and better if we have a lunch alfalah we can expect that is smaller volume will be able to give us thewhen the typical hydraulic diameter is $1 of this region where you see this is the army playing tubular steel and tube heat exchanger and on this side the over-30s address to print is a basically the heat exchanger plates antibiotics ninjas and the crimes are you texting us all all that type of metrics and other a text and just basically belong to that you know compact heat exchanger Ranger hydraulic diameter of this is why we have the hydraulic diameter and this is why we have the surface area density so dearly about 700 is the demarcation between the compactness and the non compact heat exchanger Sophia somewhere here we have the that 500 600 700 that’s the limiting line between the compact and non compact heat exchanger so basicallyunderstand that this is the length and we have one free flowing from one end to the other and directly from design to design and I need fluid it is entering hear it has to exist it can come out from this and it can also come out from desert so it is also coming this is another advantage or you can say the characteristics of display print a FedEx in there were multiple exit or intermediate entry and exit can be possible in this type of heat exchanger ok so another picture of Victoria love you and show you hear this is another late fee if you text me again can see glimpse of the fence this at the film’s sorry we will be discussing about this geometry later on so this is the glass floor tile play free antibiotics in there that this is made of elmbridge aluminium there are two towns breached and aluminium safe antibiotics and this is also a playful type attacks near which is made of aluminium and that aluminium is placed with each other so that it is a special type of pet fanatics near which is the best aluminium plating it is near so we’ll talk about this in details first of all let us have a look into the details of this way we will go for aluminium five-week low for blazing of it soI’m in this kind of exchanges are widely used in automobiles are in a club so there’s a way to strength ratio of this material is always looked after I will always look for and understand that the breaking his only option particularly for the type of things are going to be joined in case of a playful type heat exchanger we cannot do the regular welding aluminium while it’s possible we can do the welding of food surfaces with the plates are manually so we had to go for if automatic joining of the plate with the face which will be talking later on and so far this particular properties like low I will hide high strength-to-weight ratio2003/2004 any element aluminium and particularly in percentage is allowed to 1.5% manganese it will be there and it’s a solid answers 643 degree certificate so if we have a plate and we will be collecting the fence on top of it and it is like this will be joining this is the kind of thing will be joining and this is the playbusiness writing material is aluminium + 7% silicone its melting point when as soon as he and the 7% silicone in Beckham’s fibre does a salad of this pageant material this is $6.3 so that means there’s a female material Wolfman fast but this parent material will not melt and the time but this difference in temperature is Paris not so they can understand that we need a very very precise temperature for a salmon is the temperature control in the pharmacy is very very stringent and we had to maintain the temperature of the fund is basically we’ll talk about the manufacturing of that grade aluminium at fanatics near will discuss entry also at that time so we need to maintainit will oppose insulin would we need to ensure a good braking between the train and the plate but at the same time we also need to ensure that there is no you know it kind of all on formation of any liquor so that one through it with his flowing on this side and the flavouring on this site should not leak and that’s what we need to ensure soso here is the Explorer fuel for a particular layer of the platform type heat exchanger we have one layer of primary heat transfer surface area basically says that while I told in the initial earrings that this is that extended by the transport service so according to that classification we have a primary heat transfer surface area and then this is what’s the primary it was for surface area now we have another prime minister’s office side and the transfer surface area we have the extended you transfer surface area of the field so in between those two plates on the primary heater is the surface area we have some feelings or extended Hitler is the surface so now the purpose ofso that means it’s basically like this that we want to make a channel and this channel is made of one primary surface area and other primary surface area in between what we have is the fee this thing is serving but the prices are or it has been having address for surface area at the same time it gives a mechanical stability of construction stability like it’s some strength to the construction so that under pressure this will not built for this mechanical stability of this one will also be a purpose for this one so now you can understand that each of this service is to be added to this plate and this one has to be added to this place to have a good thermal joint we need a good thermal contact between these two otherwise there will be when the heat is getting transferred so there will be a registered between this phone and the plate so that is not desirable we want this thing to be completely actors tell Miley to this upper service so we need a good bonding between this point this point this point and in fact on the surfaces should be added to thisbut it is not possible for someone to make a physical joint because he first of all it will not be accessible even if it is not accessible even if it is accessible it is impossible to make or ensure that each and every part of it is joined with the primary service area I can understand that we have two primary surface area in between we have the frame and now imagine this is the cross-sectional area and we have said a fluid flowing from design to the other end so we had to ensure that the food is not spilling over from this side on this side you should not go out of this one so what we need to do for this purpose that we should have a kind of sidebar on parents so this will be wheeled scooter barricade only signed and another benefit on this side so we are confirming the liquid within this show and this job is created by this one where we had the primary surface area and the feeling and it is bounded by two side but so this is the exploded view for a particular layer and so we can expect that on top of it will put another layer so that will phone the it is an exploded view of the two layer one so here’s what we have is one fluid this is the primary service area this is another time and surface area is the primary service area and we have one free flowing from this end to desert solar system did you transfer service area of rain and now imagine we havethe primary universability this fluid to mix with this play this play is entering from these days and we have another separating plate on this side I so thought this through it this is the sample for this late we have this cyber and on this side we have another sidebar so did between this two primary services we have pain and two plates to side hurts so this is one channel for destroyed similarly on the other side what we have is this primary surface area and then we have this is the primary surface area and what we have here is sorry this is one surface area that we have another surface area here this is the confinement this is the side borders of the two side bar and isn’t the face so this whole name it becomes an exploded view and this is for this particular channel is meant for this paradeso like this we have this fluid getting distributed between several layers and this is for if it is this layer is designated for this channel and the alternator will again be for this pizza if we call it quit number and this is the trick to we have this channel designated for free to the next channel will be designated for the fluid or so like that we have this is a 2-foot stream hit exchanges and as you can understand that it’s flip flop is taking place at 90 degree so it is a cross-flow element so when you talk about the floor and it will come in and then we go for the complete collection the matrix or something like that so she has the plate this is the plate this is sidebar weasel laughing and as the name suggests the plate thing comes from this nomenclature I’m in this no enclosure this is fake this is plate and as they all the same it becomes a playful heat exchanger there's a small video this is a best aluminium plate heat exchanger so here as you can understand that this is that’s fine but we are not able to see this particular area so the fields are located at this point there’s a defence so this channel to face the fluid is flowing even find that this is blocked at this end and this is blocked at this side so that the fluid is flowing in this direction so this is basically nothing but the rectangular hollow hidden features allowing the fluid to come on this side and allow the fruit to close to this and and this black colour one where is that find one is basically nothing by the this is the other side they will come to we’ll look into this details so now you say this is what is the sidebarthis area we had the fence that I had to each other I mean with the it is based at this point at this point and this is particularly this is and always has been and here we have a signed so this is a side but if you look at the same for this particular fee this year between this and in half it is not visible at this position this that and this and it is blocked so these are the same but so when the fluid is flowing in this direction the fluid will throw these channels through these channels through this channel this channel it will play through and it will not pass or mix with the cyborg or this is the side but this is one of the side that these are The sidewalks and the fluid is not able to mix with the fluid fluid on the other side to this channel so basically this is our again across the time he doesn’t get very hard all the fluids coming not mixed it's on mixed slightly longer than this particular one so this is why not this is smaller ok so what aboutmore than 700 and metre cube that means we get very very good compactness inside to will find some of the price and he takes yes they are like really big but if they were not come back then the beans to the girl inside so as compared to the surface area density we have genetically low pressure drop any heat exchanger design and they will try to make a heat exchanger where we have high he transferred but the pressure drop penalty is comparatively smaller so here we have the the new performance desired internal performance of the heat exchanger but not a very high and the cost of lunch special drops so it is coming up on direct pressure drop and since it is made of aluminium we have the long wait for this protection yet and it is not really very costly to the particularly the fabrication technique determines its cost and the number of units which are made on the site of the alleged that determines its cost and we have I made another big advantage of this particular type of attacks in there is that it can handle large number of string in a single unit so basically that makes this different type reduction Gear multi-screen heat exchangers so it handles multiple streams for the steam heat exchanger for multiple stream heat exchanger accommodating multiple streams within a single unit is obviously and Fantasia so the gate will let alone see how this plate and he takes only allow the handling of multiple strings with innocent then we also have the advantage particularly with respect to this replacement I FedEx near is that we have the intermediate entry and exit of the free streams so that gives a big advantage your flexibility in the handling of the phrase streams so not only it handles multiple streams it also helps intermediate entry and exit of the fruit screams in the heat exchanger so make sure it’s application where are the places where we find its application so in most of the crimes unit process plants this describing at liquefaction liquefaction plants than air separation plant and then we have the original items and as I told you this is the air separation plant we have the main attraction does the word the ear is being handled and then we have the condenser boiler in between the double column unit so the condenser boiler ideal is to clear shell and tube time or tubular exchanger these days you will find heating effectiveness around and I’m in point 9295 also I’m in otherwise some of the processes willair conditioning hydraulic oil lube oil coolers in the number to link etc are banned in case of an engine made out of aluminium and sometime it is best stainless steel to make the high temperature requirement of the handling high temperature requirement in the aircraft you will find that some of the exchanges are made of stainless steel then it says we’re using the best aluminium type of gas to gascleanliness are the buses free space is one of the primary requirement for this kind of FedEx in years and in chemical process plant where the gas and guess who gets particularly service where it is mostly cleaned and they will find that best aluminium plate for antibiotics and Jesse are frequently and use another while talking about the limitations are I’m in applications of this place to aluminium plating type of protection just we can understand that when it is built aluminium plate for me to the obviously it’s high temperature requirement is limited it cannot go a more than something like you know it’s early does temperature similarity or very close to the same holidays temperature bachata on the other hand in that case you need to go for the stainless steel time-based stainless steel pegs antibiotics yet and livableI mean when the class is cancelled all very high pressured we cannot really recommend the use of this place in time FedEx in years so it is a moderate to low pressure when it is the exchanges are a man of very good news so now types and230 is heated by the process stream we cannot really have a control on this log mean temperature difference we may not happen to launch control on the overall heat transfer coefficient so we have to manage with this area across the surface area of the extended surfaces that so this is what is this pain that all of this pain is to enhance the kitchen surface area along with the mechanical stability of the construction stability so not only that it has a purpose when we have a straight rectangular plain rectangular frame we find that the floor will be developed within a few millimetres of depending on the size of the entrance length after the entrance then the floor is fully developed and there is a constant heat transfer coefficient for the integration know what we need to do is that the oven if you want to change the heat transfer coefficient I mean if it is a regular playing regular or rectangular painting channel so we don’t have that option of breaking that boundary-less soap that is also true in case of pain trapezoidal field so after sudden and translate to find that the floor is fully developed and there won’t be any change in the there is no change in the offender metric now I'mgeometry we find that the floor is the it is slightly absurd as they can’t call it an offset stupid and this is slightly after certain length this is called the land land after the slant slant this is known as Lance length of the lens length this as you can understand that as in the paper that has been shifted it has annoyed was flowing like this now suddenly the park has been broken and you know it has been shipped it like this this channel is infected so are they coming the floor after coming over here it finds that there is another fresh generation of the first boundary layerthis purpose of the subsequent is to not only enhance the heat transfer service area not only in the mechanical stability it also enhances the heat transfer surface area just because of the construction so I’m in the field is half-time in you that is the way we feel in this type of thing it is a continuous thing here you can see there is a discontinued in the field we are interacting define at regular interval but in this time this is the continuous pain geometry but still it’s a very nice gifts as the desired flow separation at regular intervals and breaking on the boundary layer at regular intervals causing enhancement in the heat transfer service and heat transfer coefficient and along with the enhancement either it was for surface area we get enhancement in the heat transfer coefficientin the rectangular plain rectangular see if we have an operation on the surface on this surface at regular rental and relief operations so then we find that it is also a kind of introductory so the fluid will come here and it will have a passage or interest on display flow will try to go inside of that fluid will try to come out of that solution so there by giving a breakage in the boundary layer, that also will be opened using plate fin type heat exchangers. Thank you, for your attention. 




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