SK285490B6 - Capillary tube heat-exchanger with separated condenser and with subcooler - Google Patents

Abstract

It is described a capillary tube heat-exchanger with separated condenser and with subcooler, handling a steam water heating at the system of the steam turbine recuperation in the classical and nuclear power plants, as well as at the systems of the centralised heat distribution. The heat exchanger includes condensing part (1) and reducing part (3) between which the water box (4) is placed. The water box (4) is divided into two halves by vertical compartment (33) with manholes, one half of which is divided by horizontal compartment (6) into topside (7) and bottom side (8). Between its reducing part (3) and subcooling part (2) is placed bottom water box (5), which is divided by vertical compartment (38) with manhole into entry (9) and output (10).

Description

Technical field

The invention relates to a hairpin heat exchanger with a separate condenser and subcooler, which solves the heating of water by superheated steam in a system for the regeneration of steam turbines of conventional and nuclear power plants, as well as in centralized heat supply systems.

BACKGROUND OF THE INVENTION

Previously known hairpin heat exchanger solutions are such that they either do not provide water heating in one installation or, if so, they do not use the built-in heat exchange surface, or they do not cover all the heating system requirements. In order to economically cool superheated steam (50 ° C or more above the saturation temperature at a given pressure), three separate hairpin heat exchangers are required. derivative solution, where in one of them the condensation of overheating temperature (convection heat transfer) takes place, in the second steam overheated by 20 - 30 ° C condenses and in the third hairpin exchanger its condensate is cooled below the saturation temperature at given pressure (convection heat transfer). Such a derivative solution of hairpin exchangers is very demanding in terms of material and production, and also has increased space requirements. These disadvantages are partially eliminated by the integral solution of the hairpin heat exchangers according to the patent specifications CZ 278 149 B6, CS 241 317 and CS 241 318, of which the described solution of integral hairpin heat exchangers having all three parts, i.e. condensation and subcooling. The subcooling section is located above the tube sheet on the inlet side of the heated water in the case of vertical hairpin exchangers. Problems with its sealing have led to this subcooling part immediately adjacent the condensation part and thus flooded with the condensation of the heating steam and the second part of the tube bundle on the outlet side of the heated water. This tubular part, with respect to heat exchange, is an unused (loss) surface, the size of which depends on the difference of the heat exchange surfaces of the subcooling and precipitation part, which is located on the outlet side of the heated water. The integral solution of hairpin heat exchangers with precipitation, condensation and subcooling in one housing body, besides the above, does not allow different values of flow rates of heated water in its individual parts, which are, however, frequent and necessary in terms of heat exchange efficiency in heating systems.

SUMMARY OF THE INVENTION

SUMMARY OF THE INVENTION It is an object of the present invention to provide a hairpin heat exchanger which avoids these disadvantages. The task is solved by a hairpin heat exchanger with a separate condenser and subcooler, which is based on the fact that between its condensation part and the condensation part there is an upper water chamber divided into two halves by a vertical partition with manholes, half of which is divided into a lower water chamber, divided by a lower vertical compartment with a hatchway into the inlet section and the outlet section, is located between the precipitation section and the subcooling section.

The effect of the solution is qualitatively and quantitatively different from that achieved by the prior art and qualitatively exceeds the level of effect achieved by the prior art solution of this technical problem. The advantages of such a hairpin heat exchanger according to the invention are that the space, material and manufacturing requirements are reduced compared to the prior art derivative solution with three separate hairpin heat exchangers. At the same time, the problem of the flooded unused (loss) heat exchange surface in the integral solution of the hairpin heat exchangers with the precipitation, condensation and subcooling part in one housing body is eliminated. Not least is the hairpin heat exchanger according to the invention also permitting different values of flow rates of heated water in its individual parts, which is not possible in current integral solutions of these devices. The condensation part, the precipitation part and the subcooling part need not have the same jacket diameter. The diameter of the casing of the precipitating portion and the subcooling portion may be smaller or larger than the diameter of the casing of the condensation portion, depending on the flow of heated water flowing through these portions, thereby allowing increased heat transfer through convection and thereby reducing the heat exchange area of these portions. It follows that the solution of the hairpin heat exchanger according to the invention eliminates the disadvantages of the derivative and integral solution of the hairpin heat exchangers and allows their common advantages to be exploited.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is explained in more detail by means of the accompanying drawings of a hairpin exchanger with a separate precipitator and a subcooler, of which FIG. 1 shows an arrangement of its individual parts, and FIG. 2 shows the flow of heated water and heating steam through a hairpin heat exchanger according to the invention.

DETAILED DESCRIPTION OF THE INVENTION

The hairpin exchanger of FIG. I consists of a condensation part 1, an undercooling part 2, a precipitating part 3, an upper water chamber 4 and a lower water chamber 5. The condensation part 1 consists of an upper shell 12, an upper U-beam bundle 13, an upper impact plate 14, an upper inlet neck 15 The subcooling portion 2 is formed by a lower shell 18, a lower U-tube bundle 19, a condensate inlet throat 20, a lower condensate outlet throat 21, and a lower conduit 22. The shrinking part 3 is formed by a central shell 25, a central U-tube bundle 26, a lower heating steam inlet 27, a heating steam outlet 28, a central impact plate 39 and a middle tube sheet 29. The upper water chamber 4 is formed by an upper intermediate casing 36, a vertical partition. 33 with hatchways, horizontal partition 6, upper section 7, h a heated water inlet throat 30, a lower section 8, an upper heated water outlet throat 32, an upper hatch 34, and a heated water bypass outlet 31. The lower water chamber 5 is formed by a lower inner shell 37, a lower vertical partition 38 with a hatch, a bottom 11, an inlet section 9, a lower inlet opening 23 for heated water, an outlet section 10, a lower outlet neck 24 for heated water, and a lower hatch 35. of the heating steam by the hairpin heat exchanger according to the invention is apparent from FIG. 2, wherein the heated water flows through the lower inlet throat 23 of the heated water into the inlet section 9 of the lower water chamber 5 from which it enters the lower U-tube bundle 19 of the subcooling section 2, from where it flows into the outlet section 10, the lower water chamber 5 and the subcooling. part 2 exits the lower outlet neck 24 of the heated water. The lower vertical partition 38 with a bypass passage hatch allows bypassing of the subcooling section 2 shown in FIG. 2 marked with a dashed line. The heated water from the subcooling section 2 flows through the upper inlet 30 of the heated water into the upper section 7 of the upper water chamber 4 and from there to the upper U-tube bundle 13 of the condensation section 1. From there the heated water flows into the second half of the upper water chamber 4. From this, it flows into the lower section 8 of the upper water chamber 4 and leaves the hairpin heat exchanger 32 through the upper outlet neck 32 of the heated water. The vertical partition 33 with bypass holes in the upper section 7 and the lower section 8 allows bypassing of the condensation part 1 as well as bypass of the precipitation part 3, which bypass is also possible by the bypass outlet 31 of the heated water. On the heated water side, it is also possible to bypass the condensation part 1 and thus the precipitation part 3 through the by-pass opening of the horizontal partition 6. These cases of heated water by-pass are shown in FIG. 2 marked with a dashed line. Heating steam flows through the lower inlet throat 27 of the steam into the shrinkage section 3 where it flows around the central U-tube bundle 26 and from there through the outlet steam throat 28 and flows through the upper inlet throat 15 of the steam to the condensation part 1 where it condenses on the upper U-tube. The heater steam condensate leaves the condensation portion 1 through the upper outlet conduit 16 of the heater steam condensate and into the subcooling part 2, where the lower tubular bundle 19 bypasses the condensate inlet conduit 20 of the heater steam and exits the hairpin exchanger through the lower condensate outlet conduit 21.

Industrial usability

The invention can be utilized in any water heating or in addition to conventional steam turbine regeneration systems and conventional and nuclear power plants and in centralized heat supply systems. other medium by means of superheated steam, in which its superheat, condensation and liquid heat must be used.

Claims (5)

PATENT CLAIMS A hairpin heat exchanger with a separate condenser and subcooler, characterized in that an upper water chamber (4), divided in two halves by a vertical compartment (33) with manholes, is located between its condensation part (1) and the precipitation part (3). one half of which is divided by a horizontal compartment (6) into an upper section (7) and a lower section (8) and between its precipitating part (3) and the subcooling part (2) is a lower water chamber (5) divided by a lower vertical compartment (38) with a manhole to the inlet section (9) and the outlet section (10). Hairpin heat exchanger according to claim 1, characterized in that the vertical compartment (33) with manholes has a by-pass opening in the upper section (7) of the upper water chamber (4) or a by-pass opening in the lower section (8) of the upper water chamber. or a by-pass opening in the upper section (7) of the upper water chamber (4) and in the lower section (8) of the upper water chamber (4). Hairpin heat exchanger according to claims 1,2, characterized in that the horizontal partition (6) of the upper water chamber (4) has a by-pass or no by-pass. Hairpin heat exchanger according to claims 1 to 3, characterized in that the lower vertical partition (38) with the hatch of the lower water chamber (5) has a by-pass or no by-pass. Hairpin heat exchanger according to Claims 1 to 4, characterized in that the upper jacket (12) of the condensation part (1), the middle jacket (25) of the precipitation part (3) and the lower jacket (18) of the subcooling part (2) have the same diameter. or the upper casing (12) of the condensation portion (1) has a larger or smaller diameter than the middle casing (25) of the collision portion (3) and the lower casing (18) of the subcooling portion (2).