RU2489646C1 - Steam and water heater - Google Patents

Abstract

FIELD: power engineering.

SUBSTANCE: steam and water heater comprises a vertical body, inside of which there are tube bundles installed, connected by a tubular space to a central header of heated water. In the upper end wall of the body there is a steam supply hole. The heater is equipped with a diffuser, formed by a socket connected to a steam-supply hole, and a deflector shield with a central solid part and a peripheral perforated part. The central solid part of the deflector shield is located above the central header. In the diffuser there are guide partitions installed to form channels directed towards appropriate tube bundles.

EFFECT: provides for gradual expansion of heating steam flow with stable vortex-free with further even distribution of steam in the annular space of the tube bundle, which reduces local speeds of approach flow, and also corrosion and erosion wear of the upper part of a heater, reduces losses of pressure of heating steam and increases temperature head in tube bundles, and thus intensifies heat exchange and reduces metal intensity of a heater.

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Description

The invention relates to energy and can be used in the regeneration systems of turbine plants of nuclear and thermal power plants for heating feed water, main condensate and heating water.

A steam-water heater is known, comprising a horizontal housing with an upper steam distribution chamber and a tube bundle located beneath it, connected by a tube space to the end-face chambers, the steam distribution chamber being connected to a steam supply opening made in the upper wall of the housing and made in the form of a horizontal duct having outlet openings from the side of the tube bundle (JP 9257211. 09/30/1997).

A disadvantage of the known steam-water heater is the increased hydraulic resistance of the outlet openings of the duct box of the steam distribution chamber. This reduces the heating steam pressure and temperature head in the tube bundle, which increases the metal consumption of the heater.

A steam-water heater is known, comprising a vertical casing with a lateral steam distribution chamber and a tube bundle connected by a tube space to the end-face chambers, the steam distribution chamber being made in the form of a diffuser and connected to a steam supply opening made in the side wall of the casing (SU 1366780, microliter F22D 1/32, 1/15/1988).

A disadvantage of the known steam-water heater is the reduced steam velocity in the annulus of the beam due to the lateral supply of steam to the tube bundle. In addition, the diffuser of the steam distribution chamber, although it reduces the pressure head of the steam, but at the same time does not ensure the uniformity of the steam supply to the tube bundle. All this reduces the intensity of heat transfer and increases the intensity of the heater.

A disadvantage of the known heater is also the flat shape of the tube plate of the end collector chambers, which is characterized by its large thickness (up to 800 mm in high-pressure heaters of powerful supercritical turbine units), large mass, large drilling depths for pipes and a large volume of metal being drilled. At the same time, thick tube boards are characterized by complex technology and the complexity of manufacturing. The operation of such heaters is also complicated because of the need to preheat thick tube sheets.

The closest technical solution of the known technical solutions (prototype) to the present invention is a steam-water heater containing a vertical housing, inside which tube bundles are installed, connected by a tube space to the central collector of heated water, and a steam supply hole is made in the upper end wall of the housing (RU 2315235. 01/20/2008).

In such heaters, instead of flat tube sheets, cylindrical tube boards are used, which, compared to flat tube plates with the same heater parameters, has a smaller thickness, which reduces metal consumption, simplifies the manufacturing and operation of the heater.

In addition, due to the end steam supply to the tube bundle, in this heater, increased steam speeds in the annulus are achieved, which also reduces the metal consumption of the heater.

However, the prototype does not provide uniform expansion of the heating steam at the outlet of the steam supply opening. Steam, expanding sharply, becomes turbulent: the movement of the steam loses stability and becomes erratic. In this case, random vortices of different sizes appear in the flow, and the flow velocity at each point varies randomly with time. These vortices can crush or sometimes merge with each other, which increases the loss of vapor pressure and reduces the temperature head in the tube bundle. In addition, such a structure of the steam flow can lead to the fact that one frontal part of the tube bundle can be in the stagnant zone, and the other in the zone of increased speeds and, accordingly, erosive wear.

In addition, such heaters operate on wet steam from steam turbine offsets, and wet steam at increased speeds and a complex flow structure can lead to erosion and corrosion wear of the central manifold, as well as the upper parts of the casing and tube bundle.

An object of the invention is to reduce erosion and corrosion wear of the central manifold, as well as the upper parts of the housing and the tube bundle. In addition, the technical objective of the invention is to reduce the pressure loss of the heating steam and its uniform distribution over the annular space of the tube bundle, which intensifies heat transfer and reduces the metal consumption of the heater.

The technical problem is solved in a steam-water heater containing a vertical casing, inside which tube bundles are installed, connected by a tube space to the central collector of the heated water, and a steam supply opening is made in the upper end wall of the housing, while the heater is equipped with a diffuser formed by a bell connected to the steam supply opening, and a baffle plate with a central continuous and peripheral perforated parts, the first of which is located above the central collector m, wherein the baffles to form a channel directed to the corresponding tube bundles are installed in the diffuser.

In addition, a fender ring is attached horizontally to the inside of the casing, attached to its upper end wall.

Due to the diffuser formed by the socket connected to the steam supply opening and the baffle plate with the central continuous and peripheral perforated parts, the first of which is located above the central collector, as well as due to the fact that guide baffles are installed in the diffuser with the formation of channels directed to the corresponding pipe beams, it was possible to ensure a gradual expansion of the flow of heating steam with a stable irrotational motion with subsequent uniform distribution of steam along the annulus the tube bundle. This, on the one hand, reduces the local free-stream velocities, as well as the corrosion and erosion wear of the upper part of the heater, and on the other hand, reduces the pressure loss of the heating steam and increases the temperature head in the tube bundles, which intensifies heat transfer and reduces the metal consumption of the heater.

The invention is illustrated in the drawing, where figure 1 shows a General view of a steam-water heater; figure 2 is a section aa of figure 1; figure 3 - remote element B of figure 1; figure 4 is a section bb In figure 3.

Steam-water heater contains a vertical housing 1, inside of which tube bundles 2 are installed (four such bundles are shown in FIG. 2) connected by a tube space to a central collector 3 of heated water. In the upper end wall 4 of the housing 1, a steam supply hole 5 is made (Fig. 3). The heater is equipped with a diffuser formed by a bell 6 connected to a steam supply hole 5 and a baffle plate with a central continuous part 7 and a peripheral perforated part 8. A central continuous part 7 of the baffle plate is located above the central manifold 3. Guide walls 9 are formed in the diffuser to form channels 10 directed to the corresponding tube bundles 2.

Inside the housing 1, a baffle ring 11 is horizontally located attached to its upper end wall 4.

In the lower end wall 12 of the housing 1 there is a condensate drain 13. The central collector 3 is made with a supply chamber 14 and a heated water outlet 15.

Outside of the housing 1, a steam supply pipe 16 is attached to its upper end wall 4 and is located coaxially with the steam supply hole 5. A diffuser shield is welded to the pipe 16 by means of a rib 17. In addition, the shield is attached to the bell 6 of the diffuser by means of partitions 9. The bell 6 of the diffuser is attached to the upper end wall 4 by ribs 18 and is additionally welded to the wall 4 around the perimeter of the steam inlet 5.

Steam-water heater operates as follows.

Wet steam from the selection of the steam turbine through the steam inlet 5 is fed into a diffuser formed by a bell 6 and a baffle plate with a central continuous part 7 and a peripheral perforated part 8. In this case, the shield protects the central manifold 3 from erosion. At the same time, the diffuser forms stable steam flows without the formation of vortices, which uniformly expand in the channels 10 of the diffuser and then are deflected by the baffle ring 11 to the tube bundles 2. Perforation of the peripheral part 8 of the shield increases the uniformity of the vapor distribution over the tube bundles 2. The baffle ring 11 prevents wall erosion 4 cases 1.

In the annulus of the beam, the steam condenses, and the condensate after some cooling (when the bottom of the tube bundle 2 is flooded with condensate) is removed from the heater through the nozzle 13.

Heated water through the chamber 14 of the Central collector 3 is fed into the tube space of the bundles 2, where it is heated. Heated water is collected in the chamber 15 of the central manifold 3 and then discharged from the heater.

Claims (2)

1. A steam-water heater containing a vertical casing, inside which tube bundles are installed, connected by a tube space to a central collector of heated water, wherein a steam supply opening is made in the upper end wall of the housing, characterized in that it is provided with a diffuser formed by a bell connected to the steam supply opening, and a baffle plate with a central continuous and peripheral perforated parts, the first of which is located above the central manifold, and the diffuser is installed claimed baffles to form a channel directed to the corresponding tube bundles. 2. The heater according to claim 1, characterized in that the baffle ring is horizontally located inside the housing, attached to its upper end wall.

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