HEAT EXCHANGE MODULE

Abstract

A heat exchange module is made in the form of a tube bundle with medium inlet and outlet pipes, consisting of heat exchange elements of the pipe-in-pipe type and including a block of heated (cooled) medium consisting of the inner surface of the outer pipes and the outer surface of the inner pipes with an annular gap between them, a block of heated (cooled) medium consisting of the outer surface of the outer pipes and inner surfaces of inner pipes, tube sheets of the inlet and outlet chambers in which the outer pipes are fixed, the bottoms of the inlet and outlet chambers in which the inner pipes are fixed. The supply and discharge of the medium into the annular gap can be carried out both perpendicular and coaxially to the heat exchange pipes.

Description

TECHNICAL FIELD OF THE INVENTION

The invention is intended for use in the field of thermal power engineering, in particular in low and high pressure heaters, in superheaters and other heat exchangers, and can also be used in other industries that manufacture or use heat exchange equipment.

PRIOR ART

A direct-flow vertical steam generator is known, comprising heat exchange elements of the pipe-in-pipe type fixed in its tube sheets, a pipe for supplying a heating medium from above simultaneously into the annular space and into internal pipes, a pipe for supplying a working medium from below into the annular cavities between the outer and inner pipes, pipes for removing the heating medium and steam, wherein the tube sheets adjacent to the annular space have holes located between the holes for fastening the outer pipes and connecting the channels formed in the annular space with collectors for supplying and discharging the heating medium, and the inner pipes are communicated with the same collectors, and annular cavities—with collectors for supplying the working medium and removing steam (patent RU 2140608, IPC F22B 1/02, F28D 7/10, published on 27 Oct. 1999).

The disadvantages of the steam generator are:

• • inefficient filling of the housing with heat exchange elements,
  • movement of the annular medium with the formation of stagnant zones in areas adjacent to the tube sheets, diametrically distant from the windows for the entry of the medium into the annular space and its exit,
  • unorganized movement of the medium in the annular space, its poor access to the pipes adjacent to the axial zone of the steam generator housing.

A well-known heat exchanger with heat exchange tubes of the “pipe in pipe” type, which is a heat exchanger, containing a cylindrical housing with pipes for supplying a component inside the housing and removing it from the housing, located in the inlet and outlet parts of the housing, respectively, heat exchange pipes installed inside the housing in tube sheets, profiled covers with connecting flanges installed on the ends of the housing and forming with tube plates cavities for supply and removal of the component supplied through the heat exchange tubes, an inner tube is additionally coaxially installed inside each heat exchange tube with the formation of an annular radial gap between the walls of the tubes, wherein additional bottoms are installed in the inlet and outlet parts of the heat exchanger housing, forming with tube plates and profiled covers the cavities for supply and removal of components, and the cavity of the annular radial gap between the walls of the heat exchange and internal additional pipes is connected to the cavity formed by the tube sheet and the additional bottom, and the cavity between the profiled cover and the additional bottom is connected to the cavities of the internal additional tubes and to the housing cavity (patent RU 2621194, IPC F28D 7/10 (2006 January), published on 1 Jun. 2017).

The main disadvantages of this design are the high metal consumption, the impossibility of manufacturing at high pressure parameters of the working media, and the impossibility of repairing the external heat exchange pipes.

Essence of the Invention

The invention is aimed at solving the problem of reducing the weight and size characteristics of the apparatus.

The technical result of the invention is to reduce the weight and size parameters of the heat exchanger.

The claimed technical problem is solved by the heat exchange module, made in the form of a tube bundle with medium inlet and outlet pipes, consisting of heat exchange elements of the pipe-in-pipe type and including a block of heated (cooled) medium consisting of the inner surface of the outer pipes and the outer surface of the inner pipes with an annular gap between them, a block of heated (cooled) medium consisting of the outer surface of the outer pipes and inner surfaces of inner pipes, tube sheets of the inlet and outlet chambers in which the outer pipes are fixed, the bottoms of the inlet and outlet chambers in which the inner pipes are fixed, wherein the supply and discharge of the medium into the annular gap can be carried out both perpendicular and coaxially to the heat exchange pipes, the number of heat exchange elements is n, where n is an integer from 2 to 3000, and the modules can be connected to each other in sections from 2 to 1000 to obtain the necessary heat exchange surface, and the layout of the modules can be multi-pass, from 0 to ⅓ of the heat exchange elements located in the central part are made single-walled, and single-wall heat exchange elements and heat exchange elements of the pipe-in-pipe type satisfy the formula 0.1 D≤d≤D,

• • where D is the outer diameter of the pipes of the heat exchange element of the pipe-in-pipe type,
  • d is the outer diameter of the pipes of a single-walled heat exchange element.

With a coaxial supply and discharge of the medium into the annular gap, a denser layout of the modules is achieved due to the absence of pipes for supplying/discharging the heated medium on the cylindrical surface of the inlet/outlet chamber and simpler connection of the modules to the collectors for supplying/discharging the heated medium (the connection is made in the heat exchanger housing under/above the surface of the inlet/outlet chambers without increasing the diameter of the heat exchanger housing).

With a perpendicular supply and discharge of the medium into the annular gap, the universality of the heat exchange elements and their uniform distribution in the heat exchange module are achieved.

With a combined supply and removal of the medium into the annular gap, the compensation of the heat exchange surface is achieved.

The implementation of 0 to ⅓ of the heat exchange elements located in the central part, single-walled, allows to supply the medium into the annular gap without losing the useful surface of the tube sheet, wherein there is also some saving of pipe weight.

Satisfying the formula 0.1 D≤d<D makes it possible to equalize the hydraulic resistance with respect to the heat exchange elements with the annular gap, wherein there is also some saving of pipe weight.

Since the module does not have an external casing, the heat exchange surface can be filled with a large number of modules, the heat exchanger can be multi-passed using the layout of the modules, the failure of any of the tubes of the module does not lead to the replacement of the entire heat exchanger, but only to the replacement or shutdown of the module.

LIST OF FIGURES, DRAWINGS AND OTHER MATERIALS

The invention is clarified with drawings.

FIG. 4 shows the module general view.

FIG. 2—its embodiment;

FIG. 3—medium supply to the annular gap perpendicular to the heat exchange tubes;

FIG. 4—medium supply to the annular gap coaxially to the heat exchange tubes.

The heat exchange module consists of an inlet chamber 1 consisting of a heated medium inlet pipe 8, a bottom 4, a tube sheet 5, blocks of a heated and heating medium 2 consisting of outer pipes 6 and inner pipes 7, an outlet chamber 3 consisting of a heated medium outlet pipe 10. The inlet and outlet chambers may include a shell 9.

DETAILS CONFIRMING THE FEASIBILITY OF EMBODIMENT OF THE INVENTION

The heat exchange module works as follows.

The medium flow through the pipe 8 enters the inlet chamber 1 and then enters the annular gap between the pipes 6, 7 (FIG. 3, 4), into the pipes 11 of single-wall heat exchange elements (FIG. 4), where it is heated by cooling the heating medium. The heated medium enters the outlet chamber 3 and through the pipe 10 (FIG. 1, 2) is removed from the heat exchange module. The flow of the heating medium enters the space between pipes 6 (FIG. 3) and pipes 6, 11 (FIG. 4) and into the inner space of pipes 7, carrying out bilateral heating of the heated medium.

The use of modules will significantly reduce the thickness of the tube sheets and bottoms due to their smaller diameter (at the same pressure and similar geometry, an element with a larger surface area will have a greater thickness to maintain strength).

Thus, a 1.9-2 times reduction in weight and size characteristics in comparison with the prototype has been achieved.

At the same time, the design of the heat exchange module can be operated in a wider range of operating parameters during the entire life cycle of this technological item. Failed modules can simply be replaced with new ones.

Claims

1. A heat exchange module made in the form of a tube bundle with medium inlet and outlet pipes consisting of single-wall heat exchange elements and heat exchange elements of the pipe-in-pipe type and including a block of heated or cooled medium consisting of the inner surface of the outer pipes and the outer surface of the inner pipes with an annular gap between them, a block of heated (cooled) medium consisting of the outer surface of the outer pipes and the inner surface of the inner pipes, tube sheets of the inlet and outlet chambers in which the outer pipes are fixed, the bottoms of the inlet and outlet chambers in which the inner pipes are fixed, characterized in that that the supply and discharge of the medium into the annular gap can be carried out both perpendicularly and coaxially to the heat exchange pipes, the number of heat exchange elements is n, where n is an integer from 2 to 3000, and the modules can be interconnected in sections from 2 to 1000 to obtain the necessary heat exchange surface, and the layout of the modules can be multi-pass.

2. The heat exchange module according to claim 1, characterized in that from 0 to ⅓ of the heat exchange elements located in the central part are made single-walled.

3. The heat exchange module according to claim 1, characterized in that single-wall heat exchange elements and heat exchange elements of the pipe-in-pipe type satisfy the formula 0.1D≤d≤D,where D is the outer diameter of the pipes of the heat exchange element of the pipe-in-pipe type,d is the outer diameter of the pipes of a single-walled heat exchange element.