 Researcher- 6550 Dear Mr Sunil Dutta in Kulkarni, Assistant Professor, Department of Mechanical Engineering, Vaalchen Institute of Technology, forestry In the previous session we have studied the simple ammonia water vapor absorption system. To overcome the drawbacks of ��ඛිය ලාවට්තායේතාඦිලාදේතාන්තාතාරින්ස්තාන්තාරුයින්තාරාරීයදීම්ණයදීමීමීමණම්යදීමාෙඳහ බුන්තාටිතනත්ඪ඀ලාේ්තාඞාතාම්න්තයේතා �ටා තා ට්හා�本当඗ මිාතික්ල අපිරයේයු,වව කඕෙරනි,ත් ද� formidable game swift巔,ඣ් පීම පිකත්නවඅේඥීත්. අව මඡියීරරී එදෙඳා වදයකෙල?egt�ී කෙය,භාවඪදචරිි උ඼ී�格,ශේරේඒ්,මෙ� ** simple vapour-assertion system can provide the refrigeration ** that is required, low temperature however it is COP or operating efficiency is low and so it is not economical therefore some accessories are fitted to make the system more practical as well as to improve its performance and to improve the working of the plant let us think for a while how we can improve the performance of simple ammonia water vapor absorption system that is simple vapor absorption system now we have seen the equation of COP of simple vapor absorption system and QE upon QG ratio of QE upon QG where QE is the heat absorbed in the evaporator and QG is the heat supplied in the generator so for increasing the COP either we have to increase the QE that is heat absorbed in the evaporator which is nothing but the refrigerating effect or we have to reduce the heat supplied in the generator so that will give us the increase in the value of coefficient of performance so in practical vapor absorption system that is Aquamania vapor absorption system some changes are made so that we will get the higher COP compared to the simple vapor absorption system now let us see the working of practical vapor absorption system and what are the changes made as compared to the simple vapor absorption system now you can see this particular line diagram now the major components which we have studied in simple vapor absorption system remains same but in addition some accessories are added in this practical vapor absorption system so first of all I will tell you the basic components of vapor absorption system and then we will go one by one to the various accessories which are added to make the system more practical and that is why we call it as a practical vapor absorption system now the basic components in simple vapor absorption system were evaporator absorber pump generator then pressure reducing valve then after generator we were having condenser receiver and the pressure reducing valve that is expansion valve and then evaporator so these components remain same they are not changed but in order to make the system more efficient and to improve the working of this plant without much problem some accessories are fitted now what are those accessories fitted we will see one by one so first of all the first accessory which is fitted is the analyzer now what is analyzer so first of all I will tell you the function of these components analyzer rectifier and heat exchangers which I have mentioned in the next slide I will show you first of all these accessories fitted first accessory fitted in practical vapor absorption system is analyzer second accessory fitted is rectifier and then two heat exchangers are added so we will see first of all the function of each of these and then we will study again the working of the entire practical vapor absorption system now what is analyzer now we know that inside in the generator we are supplying the heat and the heat wastage which can be supplied by using either steam or hot water or any other form of wastage which is available so in generator we receive the strong solution of aqua ammonia and the function of generator is that we want to separate the ammonia vapor only should pass to the condenser and remaining water should go back to the absorber because it will be available for absorbing the ammonia vapors coming from the evaporator so in simple vapor absorption system the problem was that though the ammonia boils off because it boiling point is left there are chances of carrying off some water vapor also some water droplets may also be carried with the ammonia vapor to the condenser and if they go to the condenser then they may get choked in the particularly expansion wall after reducing the pressure and which will cause choke up of the pipeline or expansion wall therefore our aim in practical vapor absorption system is that only pure ammonia vapors should only enter the condenser no single droplet of water should go to the condenser that is the main objective so for separating the water vapor which are carried with the ammonia vapor what we do is that when the strong solution is pumped to the generator it is not directly going to the generator it will pass through the analyzer now in analyzer is a small heat exchanger in which the horizontal zigzag plates are airing so this particular strong solution will fall down and it will come in contact with the hot vapors of the ammonia which are going out that is why the effect of this is that the ammonia vapors which are going out are getting cooled so any water droplets which are present in this they will be condensed ok and this solution which is entering into the generator ok it will get cooled little bit and so we will be able to separate out the water vapors in the using the analyzer ok so it is a small counter flow heat exchanger only now after passing this they are entering into the rectifier or dehydrator this is again a small heat exchanger so even if 98% of the water vapors are separated in the analyzer there are chances that 1-2% of water vapor may remain in the ammonia vapor so they are further removed by cooling these ammonia vapors by using a rectifier or dehydrator so the remaining water vapor if any present it will be condensed and it will be sent back to the analyzer through the drip and then which will be going to the generator so the function of this entire assembly of analyzer and rectifier is to remove the water vapor from the ammonia vapor now after removing this water vapor the pure ammonia vapor will go to the condenser and this in the condenser as we have already seen in the simple vapor absorption system the condenser remains function of condenser remains unchanged it will condense the high pressure ammonia vapor into the high pressure liquid so at the outlet of condense we will get the high pressure ammonia liquid because ammonia is the refrigerant which is stored into the receiver and then it will go to the evaporator but in practical vapor absorption system we are not directly supplying this particular liquid which is coming from the receiver to the expansion wall we are passing it through the heat exchanger now what is the function of this heat exchanger the function of this heat exchanger is that this particular liquid which is coming out from the condenser and that is the receiver ok it goes to this whereas the after absorbing the heat from the evaporator whatever ammonia vapor is going over here it will be passed through this now this ammonia vapor is comparatively colder it is colder compared to this liquid which is coming from the condenser so what we do is that we try to absorb the heat ok from this condenser the liquid and then we are trying to subcool it so the effect of this will be this is sort of liquid suction heat exchanger you can see we will get the subcooled liquid ok at the entry to the expansion wall which will definitely increase the refrigeration effect as we have seen in vapor compression cycle whereas it will cause little super heating of the vapor which is coming out of the evaporator now in case of vapor absorption system super heating has got no adverse effect so after absorbing the heat from this liquid this particular vapor then goes to the absorber and where it will be absorbed now further working is same but again in this system we are not pumping it directly to the generator the strong solution which we get after absorption of ammonia vapor into the absorber it is passed through the heat exchanger because this solution which is going back ok we want to what you can see heat it whereas the return weak solution coming from the generator is hotter we want to cool it and then we will reduce its pressure so here what happens you know we cool this return back coming solution from the generator and we try to heat this strong solution which is going to the generator using this heat exchanger so effect of this is that it will reduce the heat to be supplied in the generator at the same time it will reduce the heat to be removed in the absorber so this causes because we are using this heat exchanger we are achieving one thing we are reducing the heat required in the generator so COP will be more at the same time we are trying to achieve the sub cooling so this refrigerating effect will also be more so the other working remains same as like a what you can say simple vapor absorption system so as we have seen these are the three accessories which are fitted analyzer rectifier and heat exchanger we have also studied its function these are the references thank you