Heat Pipes and Heat Pipe Heat Exchangers – Part 2





Hello everyone, if you recall we have started a new topic in the unique heat transfer equipment we are trying to learn that is heat pipe. And as I have told you, heat pipe is not a heat exchanger itself heat pipes could be part of a heat exchanger and when it is used to construct a heat exchanger which are known as heat pipe heat exchanger, they are very efficient in transporting thermal energy. That way for a small temperature difference they can transfer it and told him it was got wired operating range etc which evening but still we are in the introduction to you later see how is this device what are the basic features etcetera topic which I am continuing is 85 cents each bite in exchanges and the last lecture what I have said that she's basically shut up anda number you just forget the number because the number will change but I am going back to that slide so that it will be easier for you to come to the previous client of the previous lecture this is the construction of it for now let us try to understand construction and then go back what we can see that it iswe will have certain amount of liquid which is known as pink working through we will discuss sometimes regarding the working through it he working fluid has got a very large range crying if we could be there there will be liquid metal working and once you to be working through it then generally this metallic cylinder iswhich three done part of me from the condenser to the bridge now if we come to this diagram once again so there is an evaporated section where heat input will be there where the heat 5 will receive it from outside inside there is capillary structure within this container for this container the blue colour is the container the capillary structure there is Carter Carter with him we can see the capillary structure by the by this grey colour we can see the capillary structure so here there will be liquid and this liquid evaporate so here there is a paper space and the paper is moving in the opposite direction here it will condense and come back so evaporated section 10 sub-section in between there is there is an adiabatic section very negligible amount of heat transfer takes place at inside there is a capillary structure and the work includes the construction of a common most conventional and as the name suggests that it is it is having a pipe like structure and most of the cases it is like it is having some sort of a circular cross-section it is not mandatory that should have a circular cross-section we will see later on but that was the earliest design or initial design and that is the design till today for most of the year now let us go backthat I have done is known as the evaporator the other entities registered and this is known as content such as the name suggests in the evaporated section evolution will take place and in the condensation condensation phase changes involve that is very important between the condenser and evaporator should ideally be a diabetic or impractical cases they’re very small amount of heat transfer from the ocean which is sandwiched between the evaporator section at the college the tubular structure of thecontainer only partial to this is also I have told sometimes the evaporated and condensed rejection might have external features to enhance the outside heat transfer through this part we will see later on also but now let me explain it that what I like to what I like to see let's see this is the 85 from outside it just like Louie like you so this side is the evaporators this side is the evaporator section and decidedly condenser section so on these parts there could be because heat pipes can transfer heat from one class to another galaxy from a hot hot gas to liquid gas outside we can see that gas is there or basically if I can be part of a gas to gas heat exchanger so yes I did transfer coefficient is very small so to improve the gas I did transfer coefficient feels like this these are radial fence if we see a cross-section to the cross-section could be like this so this is the Queen this is the tubular wall and this is the capillary structure so this is feel this is u-haul and what I have shown by this dotted line this is the week okjust mean type of way week is nothing but some kind of Barbies and they were miss baby one layer of awareness of civil layer of dermis is get inside so you can see this is with you all and yesterday just want to beat you all close to the cue ball we have got where mess with this is called your screen that suppose this is the tube and tube we have groups and all channels are groups so which is shown in the diagram on the right hand got this group structure to this group structure also provide clarity and also provide the written part of the contest we have got and here we can combine that means here we have got glue and that the outside of the group we have got screen or work through it is a combination of channel covered with screen or where is the where maize that can be slightly away from the wall here so we can see there is an annular gap between the wall and the very best to this and in the gap is generally filled with condensate or liquid and this can be also one design for the return part of the quick then there is something called there is something called artichoke pizza for high-performance heatpipe so here we can see that there is a special structure and these are mainly the news was there in space system we will find or we will discuss that in space there is a lot of space crafts and space systems there are a lot of application of heat pipes so there we need a good thermal control reliability and for the reliability with her to ensure very efficient and reliable return part of the equation so there is a structure which is called Italia kind of this there could be some other design many other innovative design of the capillary structure soap speed inside video for this is what it could be that we are providing some shut up or groups small boobs this could be small for the clarity is in action this is another car that there is a solid metal wall inside the solid metal wall just adjusting to eat there could be a centre Doris layer of this ruby open course should be connected to one another but did not be straight for so there could be some sort of circuitous route or kind of ginger root because the different ports are randomly selected so that could be another way so here we can see this is the outer tube and this is the centre clear to this is also another way of structuring the principal main ways of having the capillary structure has been describednot be able to spend very large amount but some of the unique variation let us let let us discuss with this Rider that these are not all inclusive there are many variations of I like to show at the top of the flaglong long way to the diagram it could be long but this is a flat file and this flat pipes are very handy when we have to go for compact systems electronic component cooling of laptops and some such devices we will see another photograph later on so this is then I am coming for some sort of a new kind of the structures below is known as loop hit by a loofah the difference between your normal heatpipe and route 85 is that in the normal heatpipe again let me explain it later that will be normal heat pipe is something like this normal heat pipe is something like this let's say this side is evaporator there is capillary structure inside paper moves in this direction and here it is condenser so this is your condenser this is your evaporator and liquid moves in this container is actually if we take a cross-sectional view then this is paper andhere we are again look it look it and you see the blue colour blue colour shows the liquid what liquid liquid line and the red colour here for the gas line on a pipeline so there is a structure the structure is very important this is kind of a structure which is having number of compartment one there is a will there is a Peugeot evaporator in the lab then priming week or etc so one has to go into details otherwise it will not be in a short time it cannot be described but what we can see basically that liquid pot and papa are different this is called Blue look then on the right-hand side up for what is known as a pulsating loop it by 4 call city so popular leaders is known as popularly this is known as PHP pulsating it fighting it by the advantage is that that there is no fee structure there is kind of meandering of serpentine kind of pillow and through this through there will be alternate path of liquid plug their butts class like that and there will be some sort of a pulsation as you can understand but ultimately the paper class will go to the condenser section they will be generated in number block number in the protection they will go to the concert section they will condense over there and mostly liquid along with some small number of liver box will come back to the operator again number of paper plusdiagram that we have bought one number 12323 down sit there and if we increase the number of times then what happens this one sitting loops by Gary operate at any kind of orientation if there is less number of dance with evaporated has to be at the bottom part of the heat v condenser has to be at the topmost part of the fight but if we can increase the number of there could be very large number of 50 5062 large number of times and then we will have that it becomes independent of gravity at any in any orientation this kind of pipes can open it should be a very very small inclination that normally alwayslunch possible and what one can have by being redesigned intelligently one can have different kind of advice for different education now this let me go back to the next slide this is one slide is why are you see if you offered her that I have written this is a black paint heat resistant laptop in laptop if somebody has opened probably one can see the laptop this kind of little bit of time and explain what is the working principle in the laptop you know all the all the all the equipment electronic equipment thermal management is one of the problem and the electronic component that we generate heat that has to be dissipated very efficiently so what we can see that here there are lot of generation and so from here it has to be picked up so it has to be picked up this is picked up by the evaporated section of it this is basically let me draw inside only 85 is basically having some sort of structure like this so you need not have the feeling that the pipe is always a straight buy this is the best buy even more crooked kind of configuration is possible you see this is bent and this is flat so the heat pipe from the evaporator section it will pick up it and then it is going here this is your condenser now this is the condensate section in the concert section ultimately the heat has to be given off by the given up to the MBA show here for efficient transfer of heat what we’re having this condenser on the condenser section we are having pills which I have mentioned earlier so basically we are having number of things over there so here it isthis is the plan even been to this is the connection section here the house I did transfer is enhanced by providing funds and by providing an air flow of a different structure it is ultimately deposited or rejected to this is one of the very important component of your laptop the laptop will not perform well if the thermal management is improper and you see in the thermal management is taking a very crucial information I like to end my lecture today and so thank you and I think this has given you some sort of exciting information for a very unique transfer equipment which can be used in different applications. Only one application we’re seeing today that is your laptop but there could be different applications I will come to that, advantages, limitation, design etc, I will come to those aspects, thank you.