Plate Fin Heat Exchanger: Multi-stream - Part 1
Welcome to this lecture, we are going to talk about the plate fin heat exchanger where it will be handling multiple streams, multiple fluid streams. So while talking about the plate fin heat exchanger characteristics we have told you that one of the characteristic features of the plates fin type heat exchanger is that it can handle multiple fluid streams in a single unit. And that we take it as an advantage because several for extremes in a single unit can OpenOffice high degree of compactness and also eternal performance enhancement in the tournament so if you look at the bike tyre fitter trade to multiple single-unit how it has to be done so since we had talked about the extreme geometry just give me an answer and on the brute strength of autism understanding we have shown only triplett Street so hear one of the fruit free is free number 131 so it is so at this side and it is moving out from this site so as you can understand that this is the first train entering from these openings wheels with bearings and so many other side of which year at the is it in this layer particular layer it it will be coming out from behind and finally it will move out from this side now what about the other person’s say fruit stream to this is entering from this side and you can understand that this is been there too so it will be coming in from this side the side and this side so she is this letter is for designated for free stream to this is phosphorus 32 verses for strength to like that and they are all coming out here on this side so what's theis going out from the side like that the oven that is 321 and berries repetitions of this again 321 and so on so it is like that it will be arranged so if we look at the show me to particular geometry of this particular here and if we respect our self from Brooklyn to this plant we find that the three floyds streams are you know this is the first country is entering from this side and this is moving out from this site where is the very next 48323 to centrelink from this side and moving out on this side so they are in Compton current configuration so if they sprayed 3 is entering from this end and the Pluto is there to inform this ain’t so they’ll encounter current configuration within the span of the exchanges must about the fruit stream 103.9 that it is 30 as it looks like awhat’s the best route to in contrast to the fluid to the free to is moving from being sent to that and the flight number one is entering from this sent to this side and that means this is also encounter current to this so we can see that this street stream 123 our encounter correct configuration with each other so the three of you coming here at 3 will come from this site it will come out from this side and two will be coming from listen to recent am so angry trout streams are in contact current haven’t went to each other well as it will be open or it may look in a countercurrent and cross flower arrangement but internally within this month there is counter-current configuration so this is one of the beauty ofdistance can be up I’ve been as many as 11 number in I mean we have come across it and just family 11 number of extremes and I know that this particular type of pig is that we may go through it at some intermediate science that means intermediate entry and intermediate exit is also possible entry of the flu strain and intermediate exit of the fruit stripe or intermediate English of the first term is possible that means it’s not necessarily inter from decent and come out from this and I will travel all the way to this lady length and come out from this and if someone wants you know it may be taken out from thisincluding the first train from different social media and drink immediately and that is possible picture when we can seeso this is one end and that is something that is an intermediate and this is the first time for outlets 22 outlet self-esteem to inlet and this is like the fluid for removing out stream the screen 5:00 it is not showing the entry sewing the entry of the other strength which must be located on this side on the side ofcounted as well as government is likely between the fruit strips so it will depend on the optimum store in a certain we’ll talk about that you can understand but when we have say ABC fluids of a b c d e r number of fruit streams then how do I arrange them that also you know some kind of possibility possible configurations like we should go for a c c e r t like that this combination of we will having them in a different combinations and how this pattern will the layers starting past and we will discuss about that but sometime later so when we talk about this kind ofthat means we know about the Google dimensions of the configuration of the heat exchangers and we know the English poet and conditions so that we have to find out the performance of this affect antibiotics and yes I will try to find out for the exact word streams temperature and the pressure so how to do that even try to understand that one and the associated problem with this particular type of heat exchangers so we will look into that so now imagine that this particular example we will be showing you are to demonstrate why this designer simulations were particularly is completed in case of abetment I feel ashamed of anything that we have a place to purchase all the questions are entering our from inside designed to listen to I mean entering from the side and moving out from the other side except 1st Street that we have this 3% there in parallel combination to each other but this stupid since our in-country current configuration audit may be of a different configuration also it may so happen that at the Footscray one in entering from this side say another place trailer that post I will re-add which was there at this location now we have this on this side and this is the other so this is great stream 1262 sorry this was for right this is 2 and ¾ 1/2 we are entering from this that and the other oneas compared to the other situations we have talked about so far so here are the fruits teams are entering from one end and we need to find out the exact temperature of the exit precious at this side when it is not known and what we do is that we go step-by-step if we divide the interest in going to snow peas and what we try is if it is divided into a spray the small piece and we can try to find out the exact temperature at this point so we know all this temperature as this and it is known as the space and we can try to find out the temperature at this location so if we can find out the temperature at this location so it will act as an input for the next session and will be able to calculate the exact temperature for this tiny in length of the edges so it will keep on integrating from this led to this direction I mean for mexico’s 20 2x equals 12 and we’ll be able to finally get an exact temperature at this end so that’s what is the process went on the Fritz trains are entering from wind and moving out to the other side so all the pistons are in parallel combination to each othersituation is not that if three of them are entering from one side at least and one of them is Uno coming from the other side so if this is the situation then what happens so we can make the an estimate of safe and said there’s three because here at this point if we have to make a small section of this action yet but we need maybe you will be starting from this end and that there’s all these three questions that I made temperature pre-strip temperature salon and so we have it it is convenient to stop all this and if we just assume only one fruit stand temperature for this month so we should have been a minute should be ideally able to predict the outlet temperature for today fieldstream and then you know one personthis can also be handled if we have the governing it transferred and pressure drop equations and then you try to solve it step-by-step route from design to design just by making an assumption for a single to extreme I’m in so far as the exemption is associated with the single-serve strength we have no problem so that introduce such that if we have to get the configuration is such that we have more than one field strength entering from both the ends I mean this is like we have alike you know this is great Shane Warne this is question to 1st SEM 3 and 1st 4th this is one and two are incomplete and two and three and India are in contact current management as well as she poured out again you know so I can tell him to come to encounter current arrangement in this configuration what happens is that this is has been shown by herself in her paper the percentage calculation methods for Manchester place in time predictions but he has shown that when we I mean this is the configuration that we have unlike let us look into this carefully so when this is calculated from and a that means as we were telling you that we have three friends here in SE23 for their entering from warrant and that and has been designated as a and the other end is designated as b and from being and which is the fruit showings this is the street number one that is flowing from MB to end a services and a description number one so now when they have calculations I mean started found and a that means they have made an assumption about this exist temperature and they have approved to the solution formed and a 2mp then they are finding convergence of this outlet I’m inside temperatures but look at the situation when they have started from the end brnb mints what are the things that she have to I mean she has to do is that we are coming like this so if we have to simulate from this and so one has to assume the fridge temperatures at these three points so even if someone is very close to the actual exec temperature and if someone try to our enough start simulations from NPR it will be such that you know the area very soon I mean it will bypass the solution will type it so we are not going to get any kind of solution when we are going to make a brain injury or even death will make a way Rick Ross you know I wanted to the exact temperatureopen start now I’m in literature available in different journals and books shop will look into that I mean how do I go about it so we will try to post to sell will go to the ifthe question b and c and d and they are arranged in idabel are the kind of talent combination. And what we needwhat we need to find out is how is the government transferred equations and then only you will be able to find out the solution of those governing heat transfer equation so now we need to solve this equations what we have with us is the attractions in geometry known to us and what is name is the inner temperature of all the separate state Mississippi this is strange sea inlet is known and the supposed to be in that is known all the inlet temperature and the heat of the configuration is known to now based on this we should be able to find out the exact temperature of all this fits him so ABCD exit temperature so if there are four questions when it for exit temperature then what are other things that are not known on the world temperature city we do if we designated then you know twtw to TW3 all this while temperature also you know it matters so we have been a number of fluids then we have a row in plus one number of what temperature is unknown to us so we have a number of blue string and their existing policies are not known and we don’t have information about the wall temperature for the end plus one number of separating place so all together but we expect that plus one number we need 20 + 9 + 9 + 10I am in what we need but will need is basically kind of energy balance fault on the fruit streams and particularly the extremes and I mean all that weight while compilations all the questions that they can write that we also know the last four for the individual stream.com MB dog like that all the muscle rate of the fruit strips that also known to us so if we assume that these equations I mean we should be able to write in terms of endorsed a CPA and then you know delta t a where one of the temperature is not the electrical issue but the exact temperature was not able to write CPD and then we have the data key and the TD and find that one of the temperature is known in the detector is not the temperature and if it's something and it maybe depending on its surrounding it is having some of the phrase on the side and it may be here for the 10-minute fluid it is an end cap would be there for the terminal and on the side there will be another Creed say fluid one if it is supposed to be on this side so it will have our interactionsamosa I got it made into it or it may have to give sheet to this depending on the situation of the fruit temperature all the situation may be such that it is giving it is wrestling Kurt Angle wrestling it from the bottom to it so they’re a different configuration that is possible and the simulation has to take account of that enough situations so basically what we need is a fin equation if you remember that in the last class we have in one of the earlier classes we have tried to solve the funny questions that the field is collected between two surfaces are a combined between two surfaces sata and TB and we tried to find out a solutionand we tried to find a solution for this month and that we have been able to find out in the temperature profile for that free and that was Peter x given by the teacher x and keep it was obtained as * 1 – Omega and y to the power m x + Omega into a to the power minus x and this is this one is x and y is equals to e to the power m minus our first bill is the length of this team and this is in the denominator we have find hyperbolic ml and what are all is just nothing butinternational journal of heat and mass transfer volume 39 issued to and the pages are 4-1 9 2 4 2 8 1996 sir in front if anyone of you have to the amulet you can critically look into this paper where we will get this analysis and not only that you can also look into the book we have preferred that is by Shyam shaker like they are also you will find this analysis available so now based on this feeling creation I mean we know that thing temperature profile or the temperature profile that is existing in this pin collecting between the two surfaces now once we have the knowledge of this fin temperature profile, we would be able to calculate many things which we will discuss in some of the next classes. Thank you for your attention.
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