Classification of Heat Exchangers - Part 2
 
Hello participants so we are back in our course on heat exchangers fundamental design analysis. We are continuing with the classification of heat exchangers  and that’s why in the beginning we should have at least some sort of acquaintance with the main types of Odysseus and also we should have some idea that there are some special tickets and that’s why we want to spend some time and we want to help this family ready with the family of you texting through through classification different ways of classification we are showing now we will go to another way of classifying it is tickets this slide is again very important let us spend some slide aside some time on this particular slime and here we see classification according to construction give two different requirement we have got different construction of it that there will not be changing this so we will we Will prefer to have one kind of heat exchangers one particular guy construction geometry of BF3 like to have the transfer between gastric we need to have so many other things I need to have another kind of you but would also like to be considered like let’s say the fruit strings look we are handling in the heat exchanger in one case they’re very clean there will not be any tendency of fouling we can go for one kind of unity construction is there will be any possibilities of filing so we have to be careful so that we can reduce the pendency of the filing with the design of the heat exchanger accept or we can eat provision that the Henderson opening of the heat exchanger disassembly of the it is possible within no time so that we can clean it and put everything back together to get text operation according to make sure we can have different kind of it is so first thing we see that you will I be texting you like construction circular plot type of circular cross-section that is very common in industry then we have also human being has also adopted the same thing in the design of heat exchanger Derry on it is should be texting the simplest I could be a double fine and I have fun in my in one of my earlier lecture so either it is called double bicycle inner tube in tube heat exchanger so there is a central team and there is another round he have a double type extended improvement improvement far higher capacity is sale and you’re texting so in this case the outside but inside instead of a single cube there are number of sides and three inside some free passes and to be inside some electric buses pause construction we can have crossed girl who did you buy this item and cross  we can have crossflow to the tube can you say I do not like to do it at this moment because the paucity of time so what we will do this shouldn’t you be texting Eric we will take it and very details later on so just for the timing you know that there is a cell with in which there will be a number of tubes and then there is one kind of fluid will pass through the cell site and another free will pass to the cube side but there could be very large number of variation to this basic design which we will talk later there could be could be spiral tube heat exchanger tube that is in the form of spiral there could be buy coins so I mean to increase the area within a given length all the spiral tube and equality but taking evening coyote you can be taken within yourself there are different kind of variation if you think not these are not without exception that generally cumulative still fine if two sides are equal to in many cases did not think that one should not think that they are annoyed since there are exceptions but in most of the cases if fluid is passing I mean passing through it is equally then we preferred the people that can withstand higher pressure that is one advantage and generally when liquid flow is there there could be hydration and tubular geometry also gives very good feeling so feelings is not a problem liquidity will not a prob will not be a problem so that’s why you’re double argument regence preferred when there are two liquids then the next day plate heat exchanger breast plate heat exchangerextended service what is expended surface on surface I’m in his office in a really takes part in heat transfer particularly convective heat transfer and what’s the surface area code is the transfer now what is done the basic service we can increase its area by providing by providing extended service to the primary successor to the pacer these extended surfaces are technically known as he should feel very provided to its efforts to improve the transfer yet but primarily by increasing the area of Citroen Saxoby providing insights and then you say that we can have it played Finn in a plait styles such as a plane service we can provide feeding tube thing on the external surface with you we can provide it is not like that that only internal circuit we cannot provide thing but generally that is less common and those things are small that use ordinary separating wall and it types separating 1485 is a device probably we will spend some time and that time you can understand what is the working principle of a pie or what is the working principle of hypertext and it is a very if you see any device of transferring heat from a point of high temperature to a point of low temperature we can use the extended service for since then regenerative heat exchanger we can have rotary kind of Internet we can have fixed matrix kind of regenerative and we can have rotating food security as we will spend some time on not giving any description at this momentis there some sort of different construction in Virginia and once you know this at this moment what you can do in between you can search some literature either from internet or from some book or from the reference which we have provided you so that you can have some idea regarding the generator and their construction before actually we teach it in the class so with this let us go to the next light show basic classification based on clairmont so there are two weeks I have told most of the heat exchangers are heading to fluids and most of the food itself to Freda texted me to fluids they will have some direction of flow or other any fluid will have a direction of flow with respect to the other treat this time that we have got three basic categorisation of the heat exchanger the first one is called parallel flow heat exchanger and this figure also symbolically represent the following in the same direction only on one side of the lake and I will be on the other side of the referral link then there will be counter-current kind of income flow kind of PTC India show in this flowing is mechanism or rather how we can mathematically analyse these three descriptions are very important that is parallel to heat exchanger and counterflow heat exchanger in CrossFit stated we will keep this thing in mind and see later see what are the different variation possible so let’s go to the next light particularly cross-flow head extension let us spend some time on cross fluids because they’re sucking variation in Crossville extremely different type of cross-strait exchanges has been shown in this light and it’s like so you see this is one cross flow heat exchanger this could be a plate heat exchanger you see the other person is for who was one hot fluid that is coming to this this this person is the to this person or crude will come go in this passage of fluid will go in this person who produced from the conference will come into this passage and confused will coming through this procedure will come out from the bottom of the heat exchanger have fluid will come out from the back side of the UFC heavyweight has been sold and we are showing the coordinate system which is a rectangular coordinate coordinate system x y and z andextending head with the cold food in the heart which stream is not mixing with another corporate let’s say this whole foods when is not mixing with another car twisting similarly this cold fluids dream is not mixing with another cold fluids so what will happen when the heating been on the other side of the heat exchanger the when the hot fluid is coming out it will have some sort of the temperature variation of temperature distribution when it is coming in it is having uniform temperature when it will come out it will help some sort of a temperature current temperature free same is true for people feel cold when it is coming in it will have uniform temperature distribution but when it is going out in the heat exchanger there will be a distribution of temperature that is what has been cold here here we can see another very common construction of Gospel Wikipedia so here basically there is a serpentine due to which fluid is something like this food is flowing through the serpentine to quickly so it is very suitable liquid to gas heat exchanger and then there are fees to which how many syns are there in 2 gal into the tube that is there and then fruitflow is passing through this initiative some sort of a process is made by two adjacent sides and true that the gas that is very common kind of example in case of refrigeration air conditioning and gas to liquid it is so what we called fluid is passing through this so I will be fulfilled will come out ultimately with some high temperature so here we will have more uniform temperature on gas for gas which is passing through the passage so they’re not mixing that means one thing is not mixing with the other casting on the other side we will have some sort of a distribution of the lotteryif they are not totally missed that there may be a temperature and in our analysis we need to take this is what is important and let me tell you one thing it is always or most cases it is designed to help out in some cases schematically I am showing a cross-flow heat exchanger so you see this is the gospel that exchanges this side what fluid is entering uniform temperature this side cold fluid is a very important person in the hot fluid fluid we come out so quickly temperature will increase so here we can see that the inflatable temperature it has been eaten but maximum temperature is here where it is in close contact with the heart rate this hot fluid will initially just after entering it will it will come across good friend and we have maximum temperature difference to maximum amount of heat transfer will be possible to hear the cold fluid will have the highest temperature and then it will reduce similarly the hot fluid will have the lowest temperature that the exit at this point and on this side there will be an increased this is what I had I had expressed that there will be non uniform at when there is a cross flow heat exchanger okay and this loan uniformity could be of different orders later see how how we can define some more thing regarding this morning for meeting temperature second case symbolically we have shown that one fluid is mixed and another fruit is perfect and in the parties with different art mixed there are different heat exchanger construction actually the way I have we have sold symbolically thoroughly mixed it it can not happen that way but there will be different levels of mixing see here and this is kind of a danger to hear the fluid is coming in some sort of inlet plenum and from there it is passing through the new and going to the outlet play dumb and ultimately it is going out of this is sort of a liquid that is passing through this food and then let’s see these I guess so that’s that is passing to across the tubes and then there are gas prices to hear what will happen that liquid we need fluid one that is the gas that mean are mixedit will get partially mixed or will remain our next why it will get partially mixed because here there is a plain I'm so there could be some sort of a partial mix only between prose and poetry is partially just like people it is partially mixed or and mixed what will happen if I see that we are by design we are trying to provide some sort of a mixing but if there is no mixing what will happen if this is hot which is coming and this is a cool food which is passing over details so here when the fed will come if we go to the next mini previously this idea will be clear let us go to the previous slide show in the previous slide what we can see that there is a temperature difference there is a temperature difference when the fluid is coming out for this side fluid is the hot food will be cold on this side and hot fluid will not be that cold on this difference we can we can reduce little bit that clips say somewhere in between us heat exchanger the help fluid will be cold this side so this cold heart fluid is switched over to the other side and the water hot fluid we switched over to the opposite side if we do that then we can reduce this non-uniformity this is what we would like to do this is what we would like to do let us go back to the next flight to hear what has been done here we can see that this fluid when it is coming out with one when it is coming out it is sent to the other side of the heat exchanger and from this and fluid one is sent to the front end of the day this is how we can reduce the temperature variation at the exit of the heat exchanger and this is actually fluid one is totally mixed because there is no space in between and 32 is partially mixed or unmixed so let’s go to the next slide one wheel covers only ones that is singer was he deleted the text that it covers two times then it is to pass and like that training for us we had counterflow parallel flow cross-flow split floor divided flow like this these are kind of these are kind of element which is used for in different design I don’t even see some of that then there could be multiplus multi-purpose and in multi-purpose sealant tube heat exchanger is one of the example where we use multiple so we can have in the silent you multiply 70 with exchanges parallel counter flow flow divided floor then it extended sensitive we can cross counter horse parallel and compounds all these thing I have talked and maybe as we probably will see some example and then in multiple we can have played it exchanger then seen one in person and we want I will there could be some number of passers-by to you want to buy a kickstand that the army read the latest this is basically some sort of a cylinder look like texting in between there is a splitting splitting plate oceanside fluid is coming like this it will get divided and then it will interfere and then again it will get combined and come out come out where it is coming out there only it will get combined and then two tubes filled their attitudes and fluid is flowing like this so sell-side freight first it is getting divided so one side the temperature variation will be like this other side the temperature variation will be like this then again there is a temperature with action like this there is a temperature without like this and that’s how it will come out to side of course it will be temperature variation will be almost same in both acute so this is single class single-pass meetflo it has got a special name semajay this point this Amy all capital one this is an acronym this is tubular exchanger manufacturers association this is an association which gives the codes and standards for heat exchanger design heat exchanger manufacturing it is suggesting etc to this is very important who are professionals in this field the timer handbook is very important and here by defined timer one kind of heat exchanger we have shown that is Tamar GG is the type of the only description is given for latest go to the next slide and Legacy another example shown here actually ruin is coming getting into the wire getting divided into two parts and coming out in two parts for the sell-side fluid will change and how the job site free tuition it has been shown it is self-explanatory again it is dhemaji kind of heat exchanger and we can understand how this is done then there could be classification whether it is a single phase fluid then conviction could be there on both side or it is a two-faced one side there is a fair skin or there could be raised in your site along with conviction this is how we can help exchange with combined heat and mass transfer it said this could be and considering that they will be taken up in more details later on in detail in the course. But in the meantime you can see the internet or the reference books to get some idea of these heat exchangers thank you.