RS63858B1 - BOILER ROOM, BOILER ROOM OPERATION PROCEDURE AND BOILER ROOM USE - Google Patents

Description

Description

[0001] The invention relates to a boiler room with at least two upper drums, which is also referred to as a boiler with a quick start.

[0002] In the current changing energy market, flexible supply of electricity production plants is becoming more and more relevant and boiler plants must adapt to those conditions. The main limitations for regular rapid start-up of boiler plants or rapid load cycling are thick-walled components such as drums and headers. Wall thicknesses are determined by operating pressure and the high pressures required to optimize efficiency. Thick-walled components must warm up slowly due to the thermal stress they incur, and this is in direct conflict with rapid start-up and load cycling. Due to their construction, boilers with forced circulation do not have a drum, but instead have collectors with a thick wall, however, such systems are almost exclusively used in large power plants with supercritical steam parameters. In subcritical applications, e.g. industrial technology, decentralized power generation plants, gas turbine power generation plants with waste heat boilers and power plants up to approximately 350 MW, the use of natural circulation and forced circulation boilers is dominant and at high pressure they have drum and collector components with thick walls.

[0003] DE 971951 B describes a boiler with two upper drums. It includes two separate systems, i.e. two drums are used in two separate water cycle systems. Documents FR 621429 A, US 4262 637 A, DE 975718 C also show a boiler system with two upper drums.

Description of the invention:

[0004] Patent claim 1 describes a boiler house according to the invention. The invention relates to a boiler room for heating the medium, especially a boiler with natural circulation or forced circulation or a waste heat boiler, especially preferably a boiler with angled tubes, which includes down pipes, collectors, distributors and an up pipe, which form at least part of the cycle of the medium to be heated, where at least two drums are connected to the cylinder for the separation of the water-steam mixture into steam and water.

[0005] The invention relates in particular to a boiler with natural and forced circulation that burns solid and/or liquid and/or gaseous fuels, as well as to waste heat boilers with one or more stages under pressure.

[0006] In order to minimize the wall thickness, this invention proposes to distribute the volume of the drum over at least 2 upper drums.

[0007] Preferably, the system is a two-drum system that is used specifically for heating water for the purpose of producing hot water and/or steam.

[0008] In a boiler with corner tubes, the body under the pressure of the boiler is formed by a solid, rectangular frame of down pipes, collectors and distributors. The last two are welded to the pipe walls impermeable to flue gases, forming an independent pipe body. It supports itself and any welded or separately supported heating surfaces. The load is transferred to the foundations via four down pipes on the corners, if necessary also via additional down pipes on the sides. The separation of the water vapor mixture already takes place in the pre-separators, outside the drum. From there, the steam passes through transfer pipes to the drum and the water-steam mixture flows through the pre-separators directly to the drum. The remaining water bypasses the vessel and flows through the return pipes downwards to the distributor.

[0009] A defined volume is required in a boiler for steam separation. In a boiler with angle tubes, it is possible to distribute that volume over several small volumes instead of one large volume. That volume is divided between at least two stacked drums, which are fluidly connected.

[0010] More than two drums can be placed, up to any number of drums. In this case, the stored pipes can take over the function of the drum, creating a "multiple drum". There are many places where the steam separates from the water, such as the side walls of the collector.

[0011] In the system according to the invention, in particular, the same pressure is applied in both or all drums and all drums are connected to the same water cycle system. Due to the connection on the water and steam side, both or all drums have the same pressure and are connected for the same pressure rating.

[0012] According to the invention, the ratio of the diameter D to the thickness of the drum wall is D/s ≥ 15. Preferably, D/s ≥ 18. In one embodiment of the invention, D/s is 20 to 22.

[0013] Preferably, at least one of the drums has a collector function.

[0014] That is, at least one mixture collector is designed as a drum. The mixture collector can be designed with a front or rear outlet. Extraction of steam from the mixture header can take place in the steam header. Preferably, several collectors are placed, whose wall thickness is reduced compared to a conventional drum. If several mixture collectors are designed as a drum, it is possible to omit the installation of a conventional drum. In this case, the result is a drumless angle tube boiler in which the steam/water separation volume is provided in several mixture headers designed as drums.

[0015] According to the invention, the drums are placed in the part of the boiler room with high pressure, ie. in the part of the plant designed for operation above 40 bar.

[0016] However, it is not excluded that the drums designed according to the invention are also placed in a low-pressure area. It is also possible to set it at different pressure levels.

[0017] According to the invention, the diameter D of the drums in relation to the length L of the drums amounts to: D/L = 0.03 to 0.5, especially 0.05 to 0.3.

[0018] Preferably, the diameter D of the drums in relation to the length of the drums is: D/L = 0.1 to 0.2.

[0019] The invention further relates to the operation process of the boiler house according to the invention, in which heat is produced in the boiler house and transferred to the medium, especially to water, in a cycle and the separation of the water-steam mixture into steam and water is carried out in both drums.

[0020] The invention further relates to the use of the boiler house according to the invention for the production of heat and the transfer of heat to the medium, especially to water.

[0021] The main advantage of the volume distribution according to the invention is in reducing the diameter of the drum and, consequently, the thickness of the drum wall. Another advantage of the system is the reduced mass of the boiler, since the two upper drums are lighter than one large drum due to the reduced wall thickness in each. In addition, the two upper drums improve the draw time, ie, equalize the draw time (the time between the maximum and minimum water level in the drum) with a smaller drum diameter and drum wall thickness.

[0022] It may be easier to use conventional prefabricated pipes, which are much simpler and less expensive to manufacture and install. Welded drums may not be required, which reduces costs and effort. Welded drums are difficult and expensive to manufacture due to their size and the necessary stability, and high requirements regarding statics and pressure stability must be met.

[0023] A low absolute wall thickness is possible, which enables fast start-up and shutdown in a short time of up to 1 minute, since the resulting thermal stress in the tubes is much lower than that in thick-walled drums due to the smaller wall thickness. The wall thickness depends on the outer diameter.

[0024] Fast start-up and shutdown is particularly crucial in gas and steam processes as well as in the use of solar thermal energy, as there are rapid load changes.

[0025] A better and faster steam separation takes place, since the absolute height of the water level of the aqueous phase from which the steam should be separated is lower.

[0026] Consequently, the use of pumps can be reduced.

Description of the pictures:

[0027] Figures 1 and 2 show conventional constructions of angle tube boilers as state of the art. It can be seen that different drum sizes are possible.

[0028] Angle tube boilers include a drum 1 as well as several downcomers 2, respectively. On the upper side, they include the overflow pipe 3 and the collectors 4 of the mixture, and on the lower side, they include the distributors 5.

[0029] Fig. 3 shows a boiler with angle tubes according to the invention with two superimposed drum 1. They are in fluid connection and placed in the same water-steam cycle. It can be seen that the two drums 1 provide the same volume as the large drum 1 in Fig.2, but with smaller wall thicknesses. In addition, the mass of drums 1 is reduced here and is only 148.2 t compared to the construction in Fig. 2 with 161.7 t.

[0030] Fig. 4 shows a boiler with angle tubes according to the invention in a perspective view. In the upper left, in the high pressure compartment, two drums 1 are seen, while in the upper right, in the low pressure compartment, only one drum 1 is installed.

[0031] The angle tube boilers shown in Figures 3 and 4 also include several downcomers 2. On the upper side they include an overflow pipe 3 and a mixture collector 4, and on the lower side they include distributors 5. However, unlike conventional angle tube boilers, they have two drums 1 on the upper side.

Callsign list

[0032]

1 Drum

2 Downpipe

3 Overflow pipe

4 Mixture collector

5 Divider

Claims (4)

Patent claims 1. Boiler room for heating the medium, especially a boiler with natural circulation or forced circulation, especially preferably a boiler with angled tubes, which includes down pipes, collectors, dividers and up pipes, which form at least part of the cycle for the medium to be heated, at least two drums (1) which are connected to the cycle for separating the water-steam mixture into steam and water, indicated by the fact that the ratio of the diameter D to the thickness of the boiler wall is: D/s ≥ 15, whereby the drums (1) are placed in the part of the boiler room with high pressure, i.e. in the part of the boiler room configured to operate at over 40 bar, and that the diameter D of the drums in relation to the length L of the drums is: D/L = 0.03 to 0.5, especially 0.05 to 0.3. 2. Boiler room according to any of the preceding requirements, wherein at least one of the drums (1) has the function of a collector. 3. The procedure for the operation of the boiler room according to one of patent claims 1 and 2, in which heat is produced in the boiler room and transferred to the medium, especially water, in a cycle and the separation of the water vapor mixture into steam and water is performed in both drums (1). 4. The use of a boiler house according to one of patent claims 1 and 2 for producing heat and transferring it to a medium, especially water.