00:00:00.000 --> 00:00:04.600 The boiler is the largest and most important part of the thermal power plant. 00:00:05.200 --> 00:00:10.140 In this video we will learn how a typical boiler works and what it consists of. 00:00:11.160 --> 00:00:16.660 At the end of the video, we will also report frequent misunderstandings about how it works. 00:00:18.480 --> 00:00:23.740 The function of the boiler is to convert the energy stored in coal into superheated steam. 00:00:25.880 --> 00:00:33.160 Large power plants most often use a type of boiler where water flows through the furnace inside the pipes. 00:00:33.800 --> 00:00:37.200 These boilers are ideal for high pressure applications. 00:00:39.220 --> 00:00:41.120 There are also boilers in which there is fire inside the pipes and water around, 00:00:41.200 --> 00:00:43.560 but these boilers are only suitable for smaller power plants. 00:00:45.740 --> 00:00:50.860 The burners inside the boiler convert the chemical energy in the pulverized coal into thermal energy. 00:00:51.960 --> 00:00:55.620 The hot gas that is produced flows through the entire boiler. 00:00:57.100 --> 00:01:00.640 The first thermal absorption unit is an economizer. 00:01:00.940 --> 00:01:04.840 The pump is driven by high pressure water. 00:01:06.380 --> 00:01:11.340 The economizer absorbs energy from the flowing flue gas and thus increases the temperature of the liquid. 00:01:13.580 --> 00:01:17.500 From there the water flows down the pipe to the steam tank. 00:01:18.660 --> 00:01:22.300 It then goes to a section of thin tubes called a water wall, 00:01:22.340 --> 00:01:25.240 in which the state of water is changed to gaseous. 00:01:27.860 --> 00:01:33.100 The resulting steam containing water droplets enters another container. 00:01:33.520 --> 00:01:37.720 The true function of this reservoir is to separate the droplets from the steam. 00:01:41.440 --> 00:01:45.660 As a result, the steam coming out of this reservoir is saturated and clean. 00:01:49.620 --> 00:01:52.260 Now there are some thermodynamic facts. 00:01:52.300 --> 00:01:59.040 According to the second law of thermodynamics - the higher the temperature of the heat source, the more efficient the cycle. 00:02:01.200 --> 00:02:06.800 Therefore, by achieving a high steam temperature, we get a very efficient power plant. 00:02:07.020 --> 00:02:09.560 But the temperature increase has its limitations. 00:02:09.820 --> 00:02:15.220 The material from which the turbine blades are made cannot withstand temperatures above 600 ° C. 00:02:17.600 --> 00:02:21.100 There is one more heat exchanger behind the tank, 00:02:21.120 --> 00:02:24.920 which overheats the steam and is heated to the maximum possible. 00:02:27.460 --> 00:02:31.020 Steam overheating also limits the occurrence of moisture in the steam. 00:02:36.840 --> 00:02:39.440 The steam then flows into the turbine inlet. 00:02:45.200 --> 00:02:48.500 After the steam has passed the first stage of the turbine, its temperature will decrease. 00:02:54.000 --> 00:03:01.360 A smart way to increase plant efficiency is to divert steam beyond the first stage of the turbine and add more heat. 00:03:02.680 --> 00:03:05.060 This process is known as reheating. 00:03:05.260 --> 00:03:08.940 A heat exchanger called a reheater is used for this purpose. 00:03:09.720 --> 00:03:14.980 Overheating and overheating in addition to efficiency also increase the capacity of the plant. 00:03:19.020 --> 00:03:22.420 Now let's look at the common misunderstandings about how boilers work. 00:03:23.920 --> 00:03:28.320 We know that the temperature is rising across the boiler. But what about the pressure? 00:03:31.820 --> 00:03:33.980 Consider this drop of water. 00:03:34.040 --> 00:03:36.380 Imagine being in a closed environment. 00:03:37.260 --> 00:03:41.420 If it turns into steam, the pressure will of course increase. 00:03:42.660 --> 00:03:45.700 Now consider this drop in the open air. 00:03:46.100 --> 00:03:50.480 Now if it turns into steam, the pressure remains the same. 00:03:50.500 --> 00:03:54.920 Because now the fluid does not have a constant volume, it can expand freely. 00:03:55.620 --> 00:04:01.400 Water inside the boiler is also like a drop in the open air. It's an open system. 00:04:01.500 --> 00:04:04.620 Water can expand freely when it is converted from a liquid into steam. 00:04:04.660 --> 00:04:09.260 Which means that ideally the pressure should remain the same across the entire boiler. 00:04:10.080 --> 00:04:16.700 In practice, however, due to friction and other effects, a slight pressure reduction occurs during the passage through the boiler. 00:04:18.900 --> 00:04:21.300 Save the Learn Engineering channel from extinction. 00:04:21.680 --> 00:04:26.120 Check out our website at www.patreon.com and help us with our learning system. 00:04:26.500 --> 00:04:27.340 Thank you.
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