Plate Fin Heat Exchanger: Layer Stacking
You’re welcome to this lecture we’re talking about the plate fine type heat exchangers and we will now today in this class will try to talk about the stacking pattern or the layers stacking in a plate fin type heat exchanger. And we have this is particularly important for the multitude of heat exchangers or so it is equally important in case after to see messenger also because I in it to stream it exposure also be it is not that it is limited between only two fluids that two streets are again divided into number of players so it may be such that we have to scream Street and sweet pea then this Friday and frisbee again are stacked in different layers like ab ab ab and now in context to one of the problems will takewhat is called what is called you put it in that we have saved number and one of them is hot and one of them is called said that while arranging them in the spring configuration we put them in alternative usually alternative hot and cold conditions and then we put them in this sequence ab then a then a and then in between we have saved this is b and we have PE and we said that this is when we always try to put a symmetry between the better I mean ideally should have been ab ab and so on light at it should end with a beach but generally what happens with another at the end and why do I put that one to give a symmetry in this type of configuration so that will now try to learn in this club and particularly when it is several streams are we have like a b and c c and d like that so we have different combinations like we can someone can put it at the NDC and and that would be the repetitive 1AB BC and someone may think like putting them in some other combination safe bc-ad bc-ad like that or some other combinations are there different types of layers that it would result so often we had to find out what is the optimum layers tracking pattern so as you can understand that this becomes a design problem to find out the an optimum there I mean fish optimum layer or features which is the criteria to tell that this is an optimum layout this is the best time in the year so we have to decide some kind of criteria which will correspond to and the optimum players taking pattern or sometimes the floor also designs I’m in the weather will be using say a double like a late aap then CD and then what happens with thewe need to find out what is the optimum layers taking certain so in that context we will see that say in a multiple person and I meant we may have to arrange in the same like the name of some freight moving in this side and some fluid is flowing this place and this is this moving out this site moving out coming in moving out and in general it’s all the all the food stains or rather the alterations with someone and and the school field strength we put them in another another side and Ashley can understand that it is me it may be such that we may have some flu strength which is not really belongs to the hot one of the cold ones so we may have to look for an exact intermediate positions that it will have an entree and depending on thethis moment but we’re not having intermediate entry and exit but we have clearly some fruits trees that we can distinguish that this is an extreme and this is at Coldstream how are we going to have in them to have a an optimum Louis taking certain we can call it so let us look into that first and if we actually we will try to show it to with the examples like here we have sex if this is a 5-3 stream in this 52 stream some of them are Coldstream as you can understand that the kids can we have 5% out of switch this year and this year and Disney they’re clearly deserved the entry temperature we are not a lot to look into this optimumjust because we look into this problem now when we have clearly 3 gold fruit Street and the road to Hartley Street preachers entering and 300 where is the school systems are there staring at 1 at 701 at 1 at the third one is also again you know entering at 160 so these are clearly décor screens this 17180 and 160 there the cold side streams and the other two are the hot springs now if we apply that as we told that if we solve that simulation problem that that we have discussed in the earlier classes that that multi-stream clips in detection algorithm will give us the exact temperature for responding to this so the evil come out at 2:14 thenno we also know the mass flow rate of this present and the city of the streets streets so the corresponding mass flow rate and CP being known to us we can try to calculate the what is called the key duties or what is the amount of heat that is getting transferredso they're basically as you can understand that we have to Hartford they were entering at 300 and 300 and the other one other three were entering at 7 at 160 and 170 so like this we had this arrangement of the fridge temps and then we had a visitor separating places in this was wanting me to 3493 plate number we have to respect to because this plate numbers are equally important and necessary resources and heat transfersoap out of which one is that 300 and this is 300 the first period was lobby and then we had see this is see that we had and then we had again this was quickly and this was he so this is entering the be entered at 170 degree 170 Calvin this is 170 Calvin c-murder centring at 300 Kelvin then I enter at 1 at Kilburn and he was entering at 167 so this is the repetitive block in a multiple in olx so if it is such that this b c a t e combination was giving an optimum solution according to this genetic algorithm problem problem so we wanted to check whether if it is not always possible to get a genetic algorithm how do we know whether there is a simulation is an optimum simulation or this pattern is an optimum Felton the DCA de is an optimum pattern support that the criteria that we have said is that humility he transferred so you can understand that this flu is giving it to this one similarity pieces of old Street adjacent to the hot one so the gate will be coming to this side and then this is 300 so it will be trying to decide and it will be going to this site so from this fluid at this hot wheels supposed to give it to this and this is to decide on this hot food is egalo supposed to give it to the side and decide individually we look at this is the q1 then we say Q2 and then we say Q3 and Q4 so deliberately will put up this on the strong side one as for the day so if it is still happening all the way then it will be a negative one so this is the individual hate getting transferred q1 Q2 Q3 Q4 and the cumulative is obviously their edition so we will have a look into that partso here we have the individual had loads as we have said that that is means you know that between these two three four five play late so we have he won that is equals to on this side so that’s a negative on so on this side this is a positive one and that is 15 the next one is on this site as this is a cause to a negative part on the side this is again in a positive quantity so it is outside and this is equals to 30 – on this site so we have like this a different kind of heat in all the cumulative I’m in individual it load of all corresponding to each play and now if we just keep on adding them to 715 it becomes a positive then disposed given this negative gives another positive and negative I'm interested inunderstand that if we put with the number of layers what is the number of publix a12345 and David dcr ad&e the corresponding to this we have the cumulative heat load and when we plant them with the number of players we find that what’s happening that alternative the heat load with the number of players in it is it if we consider it to be check out sometime it is coming on the negative side the very next day is it is on the positive and then it is coming on the negative side again it is going to the higher side and then coming back to this one so and indication that the simulation is correct that it will start with 0 and end with the giro and in between this check pattern that you know it is coming about the this will sometime according to the number of players in every layer it has to be on the negative side and in the next 18 has to go to the party and then it has to come with me negative and like that this will tell that thisin this context we have the Saint that this was a b c a d and e that was the optimum stacking pattern we have obtained from the genetic algorithm but it is enough and that that also shows that distributive heat load when we are floating it with the alien number that’s also reflecting the same but it does jig check petrol in the cumulative heat load that’s also it is following the animal indication of this optimum staffing pattern isgoing in and out so the optimum food stamp button it may be such that you may have to put some of the screams just the one above the other I mean in the parallel combination or parallel combination but it may be such that at any location before if the other dimension is like this I mean it’s true dimensions and if we just cut across and we could play if it was like this heat exchanger and this plane and if we find out what is the temperature of the place so I can understand that the plate temperature if we look at we will find that this is the disability plates and we have the inlet and the exact temperature should have already calculated and also I said that our simulation was able to calculate the plate temperatures so they’re separating what temperature should also TW1 gw2 etc etc and we are able to when we divideplay temperature CW1 and take this position tw18 this position and dispositions like that because this is going to Bradley with the length of the exchanges sources said the Alex and we have the other dimension so this separating I mean plate will obviously as you can understand that the fruit temperature is driving along the length of the heat exchanger and obviously the separating wall will also change with free now at any particular cross section so that means if we take are considered this particular location so we want to look what is the separating wall plate temperature between base what is the wall temperature between these two I mean point what is the wall temperature surf and different number play is this is BCA and d and e and we will look into the wall temperature actors at a particularly any cross-section at anywhere in the election in may be at the middle is maybe this and it may be on the same anywhere along the length of the exchanges but at a particular location when we have to compare we have to compare seat LS1 or at LAX to Ord and Alex zero or something like that so we try to find out what is this one temperature at a particular cross-section of the hexadecimal and find that they are more or less uniform then we say that the striking pattern is an optimistic in Belton all we can say other ways that an optimum staffing pattern will follow this kind of temperature profile along the length of the heat exchanger at a particular cross-sections so for the situation that example that we have a showing you it is first of all following that check check pattern for that the cumulative workloads and tricks to do I mean in context to the word temperature mean the program was giving us the water temperature at different locations as we have said that those play temperatures we had completed the places we have completed and at different positions I mean say this is play 1234 like that we have not taken the so there were 58 and these are the petrol prices we have considered excluding this one so we have 40% points and the plate number one is having temperature and this and like that you know we have four plate number to plug number three and plate number for the line that we had temperature at different locations and they are at a particular location they are pretty similar and similarly at different safety have to actually decided this entered into that for acquisitions and we have noted this photo apologies if we go back to that original I’m in heat exchangers picture you will find that there were four such locations as with all those temperatures were calculated so at a particular location or at a particular cross-section we find that the temperature is remaining now less similar it is not into changing much so that’s how he said that this pattern is near or close to an optimum staffing petals soap ifoptimum staffing pattern then how it is getting married that we can see it with another example this is not we’re not going to the details of this one is even understand that you have a 7 number of plates so basically we have here I’m in 6 number of pastry have 7 number of twitch streams so when the fruit stains 7 number of food streams are arranged in a pay cable optimum second part and the corresponding to the genetic algorithm spawned into that situation we find that the optimum staffing pattern is giving heat transfer along the length at a particular cross-section this is the kind of temperature at different place responding to different place and he said the different locations so what we have is more or less uniform but if it is such thatI’m in that context where we will find that the Wendy’s deviating from the actual striking pattern we find that thelike you know a particular location distance dating like this and in fact this will also the creative calculate that you know cumulative it load calculations if we do it for this configuration also we will find that this will also deviate from that I’m in that cumulatively to load will not have it and optimally Zig-Zag pattern so this will also have some kind of pattern like this and that will respond to I meant education also in the world temperature or non-uniform mall temperature so this to the wind conditions like one is the cumulative debt load and the plot of the cumulative close with the layer numbers are generally considered as because I will try to care for the optimum no particularly in case of a multi-state plan phonetically is the temperature the particular cross section at any location of the exchanges that uniform temperature in the plate temperature is another criteria to college as an optimum staffing pattern so this is all about the striking pattern and stated multiple means there are other than this cracking pattern open we had to design this is him understand that our dream realised my tab realise that this particular when we are talking about say putting the different stages ABC ad and we had initially described find pittsfield and we don’t have any information about what would be the possible animals and when we had se September 7 number of schemes like this stay in that case situation becomes very I’m in critical to physically check exactly what is the optimum staffing pattern so in that case we have to go for this journal tech algorithm program or some other optimisation we tried to find out the corresponding to the maximum amount of load we have to design problem facts and the back of this one we had that demolition program that was basically reading problems that means we went looking for a particular design are in this pattern pattern and corresponding to that second patent what is the simulation of the outlet temperature at amenity spraying that is important so a combination of both this simulation and design and goes hand-in-hand particularly in case of plate fine type heat exchanger. So thank you for your attention.
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