Assistente AI
Trascrizione
00:02:890Michele De Carli: All right, so, first of all, okay, I would like to, just tell you, okay, I have already looked the rules, okay, for both the 29th of May and the 4th of June, okay, so…
00:17:760Michele De Carli: I confirm, and I will also raise the slides so that tomorrow I will…
00:24:170Michele De Carli: Alright, so the 29th of May at 8.39, we are in the Agra Benigo, okay?
00:35:590Michele De Carli: For the written and moral part, okay?
00:40:10Michele De Carli: I will tell you the rooms, okay? And then I, I have also booked this room for the following date, which is…
00:52:520Michele De Carli: the 4th of June, okay?
00:56:180Michele De Carli: There will be, in Uniwag, there will be just one, I don't know, shall we do that, I don't know which one,
01:04:420Michele De Carli: Anyway, you book in Uniwad, and you can the day you want to do that, sir. If you come on the 29th, you can come the 4th, okay?
01:15:700Michele De Carli: Yes? Yeah, the evaluation.
01:26:490Michele De Carli: Okay,
01:35:340Michele De Carli: Yes, I can… yes, we can do that. But maybe the first Apello, the new Apello, okay, we should shift one day, because I might be busy.
01:47:330Michele De Carli: 151st? Yes, I think so. But I will let you know, okay?
01:53:720Michele De Carli: Okay, so I need also, to know how many of you will participate today first. Okay,
02:05:840Michele De Carli: Alright, so…
02:17:410Michele De Carli: All right, so we are going now to go and to start the last part of the course, which is the one related to generations. Okay, so…
02:28:400Michele De Carli: Alright, so we have seen, actually, the… We have seen, the…
02:44:480Michele De Carli: Of course, we are going… I mean, everything starts by degeneration, okay, because you have to reduce either the warm or cooler fluids, okay?
02:57:270Michele De Carli: then we go to the distribution and to the chances, okay? Of course, we, as we are…
03:04:260Michele De Carli: I hope you understood, okay? You start from the mission, okay? So you start from the sizing, so from the loads that you have to provide to the building in the different zones, okay?
03:16:930Michele De Carli: And then you go from the mission to the distribution, and then to the generation, okay? So, we have seen, both
03:28:240Michele De Carli: The air and water, since, okay? We have seen which power
03:35:760Michele De Carli: they need that, okay? And now, we are going to see how to, let's say, produce the heating and cooling, okay? So, we start with heating, okay? And, we are going to start with the, let's say, the
03:54:380Michele De Carli: most, common solution, okay? Because it's…
03:59:990Michele De Carli: it has been used for decades, okay, which is the faucetry of bolus, okay? I will go very…
04:09:40Michele De Carli: quick on that, okay? Because, we are… and then we see briefly, okay, the biomass models, pretty briefly.
04:18:579Michele De Carli: And then we will talk about heat pumps, okay? Especially air source pumps, okay?
04:26:420Michele De Carli: Of course, you have seen, like, I mean, we did combustion, so you know everything here. We'll just make you a sort of, let's say, review of the different technologies, okay?
04:40:110Michele De Carli: And what is now, what you can find out in the market, more or less. So that part will be very short, okay? On heat pumps, you, we have already introduced heat pumps in numerous energy
04:54:130Michele De Carli: technology course, okay? So I will make some breakups of that, and we will talk basically or mainly on air, source heat pumps and how to size them, okay? Because the seat pumps have been already done in the reborn and seat pump box.
05:15:70Michele De Carli: once you really… once we are going to look at the heating, okay, generation system, then we jump into the cooling, solar machines technologies, okay? And, of course.
05:29:720Michele De Carli: since…
05:31:470Michele De Carli: Now, I mean, we are working with heat pumps, okay? Of course, we will talk about reversible heat pumps, so we will see both just chiller technologies and also the reversible heat pump technologies, okay?
05:47:410Michele De Carli: Alright, and and then we are going to see if… I hope we will do also something related to how to control the
05:58:630Michele De Carli: the cooling centralized production system. Okay, and then, and then we almost finished, we are going to see the distant heating and cooling networks, okay, which is the last part of the, of the course.
06:12:990Michele De Carli: Okay, but anyway, with this, we are going to, let's say, have a comprehensive view, okay, of all the heating and cooling plants, so all the HVAC solutions that we can find in practice, okay? All right, so…
06:35:920Michele De Carli: So, this section is not a generation system, okay? This is… these are the, let's say, the layout… this is the layout of what we are going to see in the follow… today and in the following lectures, okay?
06:51:150Michele De Carli: And, yes. Okay, so, let's have, some recap, okay, of… because this is particularly important, okay, for, all the, all the generation systems, okay?
07:11:40Michele De Carli: We have seen all the types of emission units, okay, but…
07:16:750Michele De Carli: I think that we need some recap, okay, on radiators. Why? Because if you are going to work on the retrofit, on solutions for retrofit in existing buildings, okay, radiators are the usual
07:37:80Michele De Carli: initial systems that you will find in business, okay? And…
07:45:620Michele De Carli: And, okay, of course. So, I would like to, a little bit,
07:51:690Michele De Carli: On a cup, okay, that, based on a very simplified, on the very simplified, assumption that the, heating load, okay, is, so we're talking about heating, okay, so we're talking…
08:12:200Michele De Carli: So, when we talk about the, heating load, okay, we have, we can consider a linear, a linear,
08:23:330Michele De Carli: pattern, okay, a linear relationship between the outer temperature and the liver power that needs to be, okay?
08:35:440Michele De Carli: Which comes from the, okay, overall heat loss coefficients that are due to the transmission and the intellectual process, okay?
08:45:910Michele De Carli: We have seen, on the other side, when we talk about radiators, okay, the average temperature that we have in the water from the
08:56:10Michele De Carli: The average temperature that we have in the world.
09:00:660Michele De Carli: They are…
09:05:250Michele De Carli: Affecting, with the exponential function, the, or they are leading to, okay, a power delivered by the vehicle, okay, according to the increase of the water average temperature in there.
09:21:860Michele De Carli: And what we can, what we can do, we can combine them, as we have seen when we talked about radiators, okay.
09:29:600Michele De Carli: In order to have a, canicultural role, okay, which is our climate control philosophy, okay? Which means that we can, of course, in design conditions, we have the peak role for the pink, okay?
09:48:430Michele De Carli: And in this case, we can provide the maximum average temperature, which means also the maximum supply temperature of the water, okay?
10:00:280Michele De Carli: And we can decrease the supply temperature, and hence the average temperature.
10:07:460Michele De Carli: With an almost linear function, or with a linear function and simplicity, okay, when the outer temperature increases, okay, so that the radiator can, okay, can deliver the
10:26:580Michele De Carli: The, let's say, consistently, the, the power, okay.
10:31:480Michele De Carli: And, of course, this, I told you that this function is, I mean, is a self-regulation function, okay, but of course, it would be best to have also, okay, a thermostat to control the temperature, so…
10:48:420Michele De Carli: Jesus Christ took place. Well, okay, so that we can,
10:55:840Michele De Carli: reduce the mass flow rate in the radiator, and in case stop even the macroator into the radiator if we reach the desired second.
11:05:900Michele De Carli: Okay?
11:07:840Michele De Carli: So, I didn't, I didn't, I didn't tell you that, but we can, of course, I mean, with the Falco units, we don't usually use this kind of, of, contrast strategies, so usually with the, with the, with the Falco units, we work with constant temperature, okay?
11:26:620Michele De Carli: But with radiant systems, we can, in principle, work also with a sort of dramatic curve, okay? Not really if we work with condensing boilers, but especially if we work with heat pipes, okay?
11:44:770Michele De Carli: Alright, so,
11:50:580Michele De Carli: Okay, so keep in mind this, because then we are going to talk about that, too, especially when we will talk about the HIPAA technology for
11:59:250Michele De Carli: For, the generation system.
12:07:160Michele De Carli: Okay, so, now, let's start with the, secure… with the barriers, okay, so with combustion-based solutions. Combustion-based solutions.
12:18:620Michele De Carli: can be subdivided into two different, let's say, solutions. One is with the one, and the other one is with biomasses, okay? Usually, I mean, the most,
12:34:860Michele De Carli: diffuse solution is, some pandas, okay? Alright, so, what, which are the usual,
12:47:200Michele De Carli: possible, fuels that we can use. The main… the most diffuse, fuel is, the natural gas, because we have an infrastructure, a very,
13:02:630Michele De Carli: Let's see,
13:04:860Michele De Carli: diffused, natural gas network, okay? But, we can also use, in principle, the liquid, DPG, okay, the liquid, sorry, liquefied, liquefied petrol gas, okay, and the, of course, the oil, okay, diesel, okay.
13:24:810Michele De Carli: So usually these two last issues, okay, these two last,
13:32:30Michele De Carli: Puerts are used when we have not available the natural gas, okay, from the grid, while in… where we have the natural gas grid, we can use the natural gas.
13:44:200Michele De Carli: In any case, okay, it doesn't matter what we use, the,
13:50:400Michele De Carli: We have a combustion into the chamber, and then we have a heat exchanger, where the water enters, okay, is heated up, and then it goes into the
14:01:670Michele De Carli: or two, it goes into the distribution network, into the distribution system, and then, to the emission system. Of course, it will release… the water will release the heat, and then it will return with the…
14:17:850Michele De Carli: lower temperature, okay, until we reach the desired. So then, we have also a very small temperature difference between supply and return, and then the burner will shut down, and so on.
14:34:690Michele De Carli: Okay.
14:36:560Michele De Carli: So, when we look at the boilers, okay,
14:43:630Michele De Carli: when we look at the boilers, we have mainly three types of losses. Combuster losses, okay, which are due today.
14:51:930Michele De Carli: quality of compassion, okay?
14:57:900Michele De Carli: Then, we have, of course, the, the, the heat exchanger, the fuse to water heat exchanger.
15:08:500Michele De Carli: The, the bird, the, the, the, the farm, okay, are inside a case, okay?
15:17:500Michele De Carli: And usually, this case, can have some losses, okay? So, some losses, because depending on the level of insulation that we have on the case of the… of the… of the boiler, okay, we will have some losses, because here we will have greater temperature than outside, so we will have some losses.
15:37:560Michele De Carli: So we have losses on the envelope, and then we have chimney losses, because we are burning, so we are… we are making the combustion, and we have two types of chimney losses. The first chimney loss is related to the temperature level that we
15:55:460Michele De Carli: that the fuse leave each other, okay? The greater the temperature of the fuse, the greater the chimney losses, okay? And this is with burnout on, okay?
16:07:80Michele De Carli: But, as I told you, when you switch off the burner, because you reach the desired temperature in the rooms, okay, then you will have,
16:17:850Michele De Carli: worm, I mean, some,
16:22:560Michele De Carli: stored heat thermal energy, okay, in the… in the… in the… inside the… the… They boiler, okay, so…
16:33:120Michele De Carli: In this case, you have to think that you, you had, let's say, a warm body. Let's consider the water inside of the burn, and also the case of the bird, okay?
16:48:640Michele De Carli: They… this is the whole body.
16:51:320Michele De Carli: In any case, even if you stop, even if you stop the fan, okay, here you have a heat gain, okay? So, there will be, in any case, and you have an open
17:05:390Michele De Carli: In open system, okay, so you will have, in any case, some natural circulation, okay, which will, at the end, okay, cool down the body, okay, the heat exchanger.
17:19:50Michele De Carli: Okay, and these are losses that are, okay, going to the chimney, okay, in… when the
17:26:119Michele De Carli: Plan is switched off.
17:28:250Michele De Carli: Usually, okay, before, switching on, again, the barn, okay, so before buying, again, the gas, you have… the fan is operating and is removing the… the…
17:42:150Michele De Carli: the compact… the… the fuse, okay, or the…
17:46:650Michele De Carli: whatever you will have inside, okay, in order to have clean air, okay, and have good combustion for
17:54:870Michele De Carli: half a minute, one minute, two minutes, okay, depends. In any case, you have, forced probation, which is
18:02:380Michele De Carli: Also, cooling down your body, okay? It's cooling the water inside of the body.
18:08:970Michele De Carli: So, both the natural and forced convection, okay, will pull down the partner, and this heat will go to the chin, and will it turn away, okay? So, you have also the so-called chin losses, okay?
18:26:320Michele De Carli: So these are the, the, the glitching helps. We switch on, you know, of the, of the…
18:34:940Michele De Carli: Okay, so,
18:39:130Michele De Carli: Let's talk about the, burring efficiency. The burring efficiency, there was a, a big, a big change in, or increase in the efficiency of the, of, the, of the flames, okay?
18:57:260Michele De Carli: Sorry, burning the pures. When, around the 50s or 60s, or let's say, the last century, okay, so let's say 1950-60, okay.
19:10:810Michele De Carli: The… there was the switch from the,
19:15:650Michele De Carli: Partially aerated bouncer, okay, the burner, okay. And the premixer, okay, burner, okay.
19:24:780Michele De Carli: Which was releasing, which was making the possibility to premix, so to mix the air and the fuel. Okay.
19:37:370Michele De Carli: So that you could have a better, a better, and more compact frames, okay?
19:44:380Michele De Carli: And in that way, you could increase the combustion from, let's say, 60% to 80% to, let's say, 75% to 90%, okay? So that was the big, the big,
20:04:350Michele De Carli: technology, okay, step that has been done from the learner, okay?
20:10:260Michele De Carli: Then, of course, I mean, among the years, there was an increase in, okay, efficiency of the bar.
20:17:830Michele De Carli: The second technology which, which, also
20:23:60Michele De Carli: made possible to, to make, to have a better, generation, especially at partial nodes, okay?
20:33:720Michele De Carli: Because, of course, at the beginning, you have to think about the burners at the beginning, they were just switching on and off, okay, so they were not modulating.
20:42:780Michele De Carli: So the first technology was, the, let's say, to split the power into different, or into smaller, okay, burners, okay?
20:53:60Michele De Carli: So, in modular… in a modular, boiler solution, okay? So, in this case, you can see, you split the power into 3 elements, into 3 boilers, so that you can
21:05:430Michele De Carli: you can, you can go from, 33% to 100%, almost at full load, okay? And of course, when the… I mean, I won't…
21:17:590Michele De Carli: go in detail on that. But let's say that when, when you had a not enough burner, and, and,
21:25:490Michele De Carli: or enough boiler, and you are going to work at partial load protection, okay, the efficiency of a system will follow down from, let's say, 85-90%, which is the maximum, let's say, combustion
21:42:490Michele De Carli: efficiency that you have, okay? It's… here you don't have only to consider the combustion efficiency, okay, but you have also to include
21:50:310Michele De Carli: also the other two losses, okay? So the…
21:53:600Michele De Carli: the loss is enveloped, and the chimney losses, okay? So, when you are, cycling, okay.
22:01:390Michele De Carli: So, the lower the load factor, okay, the greater will be the switching of operations, okay, which will make the chimney losses
22:13:920Michele De Carli: Greater, okay?
22:16:250Michele De Carli: And… About the handle of losses, of course, there was an increase,
22:25:710Michele De Carli: the boils were better and better insulated, okay? But in any case, the problem remained at partial nodes, okay? So that was the first solution.
22:41:970Michele De Carli: Then, okay, in around the… and that was, let's say,
22:48:240Michele De Carli: These technologies were introduced, let's say, in the 91s, okay?
22:54:830Michele De Carli: At the end of the 90s, okay, neither of the 90s, okay, there was, then the,
23:03:640Michele De Carli: An improvement in the technology, in the biotechnology, which was the possibility, or let's say, the change in materials that was… were using… were used in the
23:16:780Michele De Carli: In the… in the heat exchanger, the water to fuel heat exchanger. So, going from iron cast to…
23:25:930Michele De Carli: Stainless steel. And, in that case, it was possible, okay, to reduce the temperature in order to have, condensation of fumes in the, in the, in the, the,
23:42:120Michele De Carli: in the border, okay?
23:45:210Michele De Carli: in the, the, in, especially, okay, in the, in the Chile, okay, I've been, I've been a heat exchanger, okay, in the…
23:55:140Michele De Carli: In the outlet, okay? So in that case, okay, you had a, first heat exchanger in the fumes, and then another heat exchanger in the… with the… in the… in the…
24:09:720Michele De Carli: We'd be cool mash doing that.
24:14:930Michele De Carli: With the first combustion fuse, okay? And then the other, the fuse then came into a second chamber, okay?
24:23:120Michele De Carli: and then to the chimney, okay, which has been insulated with the ocean stainless steel, okay, and then down to the door, okay? So in that case, of course, you could reduce the temperatures, okay, the temperatures of the fumes, so that you could reduce the
24:42:440Michele De Carli: losses of the system, okay?
24:48:480Michele De Carli: what I want to mention is that, anyway, okay,
24:54:90Michele De Carli: Since you're working more or less with 20% of excess of air, really.
24:59:680Michele De Carli: You can see here the dew point temperature, okay, of the fumes.
25:08:640Michele De Carli: with a 20% of excess of air, okay? And you can see that with the 20%… well, this is the curve.
25:18:270Michele De Carli: with, where you… by… you can correlate the dew point temperature as a function of excess of films, okay? Sorry, of excess over here, okay, in the combustion.
25:31:840Michele De Carli: So usually you work with 20% of this excess of air, okay? And in this case, you can see that the temperature that you have in the… in order to reach a new point temperature is 65 degrees. That means that if you have
26:00:600Michele De Carli: water temperature from the radiators, okay, from your initial system, that is below the
26:10:20Michele De Carli: Then we put on temperature, then you have condensation. Okay, so condensation occurs when you have a full turn temperature of about 65 degrees Celsius, which means that condensation occurs when the supply temperature of the rocket is
26:29:590Michele De Carli: Okay? Usually.
26:31:550Michele De Carli: less or equal to 60 degrees, okay? So, in that case, you could lower the temperature of the radiators, okay?
26:41:690Michele De Carli: And of course, you could work with a better performance. Why? Because, of course, you can, okay, you can recover the latent load of the fumes, okay, which adds
26:58:90Michele De Carli: 10% of greater efficiency, okay, on the… of the system.
27:03:290Michele De Carli: Okay?
27:04:830Michele De Carli: Okay, then it is not mentioned here, but, that was the, that was the, let's say,
27:15:310Michele De Carli: Not the la- not the very last,
27:19:60Michele De Carli: improvement in the technology, but then the other improvement in the technology was the… was the use of, modulating claims by, okay? So, in that case, it was possible
27:32:430Michele De Carli: not only to condensate the water, but also to work with a load factor, which is lower than 100. Okay, so by modulating, okay, by, by
27:46:550Michele De Carli: Modulating the fine speed, as well as the… the… the… the…
27:53:710Michele De Carli: The flow rate of the natural gas, okay, it is possible to modulate the…
27:59:570Michele De Carli: Which also made the boiler working at higher efficiency compared to him on and off.
28:09:670Michele De Carli: She's not, okay?
28:11:650Michele De Carli: Okay.
28:22:350Michele De Carli: Well, that's all, more or less, okay? I don't want to talk very much more about that, okay? Let's say that today, condensed boilers are, let's say, the
28:38:330Michele De Carli: the, let's say, the standard solution, okay? So, let me pass the course, but anyway, today is the standard solution, okay, so…
28:45:740Michele De Carli: And… okay.
28:54:50Michele De Carli: Now, okay, let's go and see the, buying my spoilers, okay? Buyers, man, buy my spoilers!
29:02:170Michele De Carli: Yes, of course. So this, what we talk about, the gas boilers, let's say, in general, the fossil fuel boilers, can be applied from
29:12:520Michele De Carli: There's more minor.
29:14:280Michele De Carli: up to… any type of boiler, okay? So, 2 megawatts of boiler, okay? So…
29:24:430Michele De Carli: For the biomass boilers, we can subdivide the… I mean, usually the size of the boilers, depending on the type of material that you're going to burn.
29:38:430Michele De Carli: And, as we have seen in renewable energy, technology course, okay, that we have basically three types of, of, of,
29:49:980Michele De Carli: sorry, biomass, okay, to feed the, the, the boiler. The, the, the cheapest one, is the, the wood chips, okay?
30:07:600Michele De Carli: Which is, I mean, very interesting, okay, but of course, is mainly, okay, due to the fact that you need to, let's say, it's a cheap, let's say, source, okay, but…
30:20:620Michele De Carli: You have to manage it, and you need some mechanical,
30:28:810Michele De Carli: You need mechanical staff and assistance, okay, so maintenance costs are quite high, so that the solution, okay, is, can be, can be valid, can be, can work.
30:41:500Michele De Carli: in, large plants, okay, so with large boilers. So in usually in, large, size heating systems, which can be used, for, I mean, for.
30:55:930Michele De Carli: let's say, industry, okay? Or can be used for this reheating solutions, okay?
31:05:250Michele De Carli: Okay, and that is the cheapest solution.
31:13:490Michele De Carli: On the other side, for very small size solution, okay, which usually do not require any particular, okay, design from the, from the, let's say, HVAC point of view, okay.
31:30:480Michele De Carli: We have the stops, okay, which usually work with wood drops or with the pellets, okay? And in this case, usually they are, let's say, heating solutions for just part of the building, okay, part of the building.
31:49:580Michele De Carli: And, and I mean, they can be used
31:54:880Michele De Carli: Usually, okay, they cannot be used for feeding or for heating 100% of the house, even though I have to mention that
32:05:50Michele De Carli: in one of the past courses of energy and buildings, I had a person who could… who said they were heating up the building just with the storm, okay?
32:15:260Michele De Carli: So, then I asked him about what the temperature they had in their bedrooms, okay, and he couldn't answer me, okay?
32:25:710Michele De Carli: Okay, so, I mean, I can tell you we did some, some interesting,
32:31:780Michele De Carli: An interesting research on that today, so you can find it in.
32:35:360Michele De Carli: the internet, where we, we, we could make, by means of simulation, let's say that you can cover from 30% to 40% of the, of the heating of the, of the building, right? But nothing, okay?
32:53:570Michele De Carli: If you want to heat up the… the small, the house, okay, with small, let's say, size boilers, usually then you use the pallet, okay? And in this case, you use a boiler.
33:10:570Michele De Carli: Where you need the… where you have some mechanical automatic filling, of course, you need to
33:17:290Michele De Carli: to, to check the progress of the story, of the palette, okay?
33:25:00Michele De Carli: And these solutions, okay, can work for, let's say, single-family houses, okay, or could be also for
33:35:240Michele De Carli: It's more, convenient, okay. But, let's say, in general, okay, they are, okay, they can work, okay, usually the, the, the, the…
33:49:590Michele De Carli: the…
33:50:960Michele De Carli: The boiler is not able to modulate that much, the power, so that usually you need to consider an additional tank, okay, where you store
34:01:670Michele De Carli: the heater, okay, this is typical when you have an on and off solution, okay, to consider an additional tank, so a storage volume of hot water that was also used in the past, in the 70s, when
34:14:949Michele De Carli: People started to modulate the temperature according to the outdoor temperature, but they were not pleasant yet in the, the…
34:26:600Michele De Carli: condensing boilers, okay.
34:30:810Michele De Carli: And, in principle, you can work for, not only for anything, but also for producing domestic autism, okay?
34:38:350Michele De Carli: I mean, it's a good solution, okay, you can work with it.
34:45:30Michele De Carli: Of course, especially if you want to replace a previous oil, Or a burner, okay.
34:55:560Michele De Carli: But in principle, you should not consider this as a solution for substituting a natural gas bottle, okay? Why? Because
35:06:770Michele De Carli: It is true that you are, reducing the greenhouse gas emissions, okay, when you work with,
35:17:370Michele De Carli: every step.
35:19:760Michele De Carli: a wood-based boiler, okay? So, the benefits are, for sure, about the greenhouse gas
35:30:120Michele De Carli: I mean, it shows okay, but on the other side, okay, despite the… Big, let's say.
35:38:480Michele De Carli: advances that the combustion, chambers of,
35:44:770Michele De Carli: of the stoves, of the boilers deep, okay? In any case, when you burn a solid biomass, okay, you are emitting a particular amount of
36:00:530Michele De Carli: Okay, and of course, this particular matter, okay, has to be considered, because it depends very much on the windy conditions that you have on the side, okay? If you are in a windy town, in a windy place, okay, maybe it is not affected that much with
36:17:160Michele De Carli: outdoor air quality, but in our conditions, okay, in the Po Valley, okay, I want to remind you that the Po Valley is the third
36:25:870Michele De Carli: worst place for outdoor care quality in Europe, okay?
36:30:600Michele De Carli: Yeah, to think about, that, when you, work with biomass boilers, okay.
36:41:100Michele De Carli: You are, for sure, helping the environment from the greenhouse gas part of you, but you are in more particular than you could end with a natural gas part, okay?
36:55:870Michele De Carli: And you can see here, okay, that from 2005 to 2015, the transportation, they reduced the particular matter. Also, the industry, okay, made a very big effort in reducing, but you can see that the heating, okay.
37:15:50Michele De Carli: raised a lot of the particular method. Okay?
37:19:500Michele De Carli: Okay, so… That's all for, for this path, okay? I think you had quite…
37:30:270Michele De Carli: wide overview, okay, and of course, if you need more information, you can find information for, for mostly burners, and boilers, and it's plenty, okay, in internet, but I think it's enough, okay, so we don't have to go really much in detail, okay?
37:50:80Michele De Carli: Okay.
37:55:910Michele De Carli: So we stop.