Indirect heat exchanger

Abstract

The utility model discloses an indirect heat exchanger, which belongs to the technical field of flue gas heat exchange and comprises a heat exchange branch pipe, and a heating medium flows in the heat exchange branch pipe, transfers heat to the outer wall of the heat exchange branch pipe and is contacted with flue gas outside the heat exchange branch pipe to realize heat exchange; the collecting pipe is used for connecting the heat exchange branch pipes; the heat exchange branch pipes and the collecting pipe are arranged in the heat exchanger shell; a heating medium enters the heat exchanger shell through the first heating medium inlet and the second heating medium inlet; the heat medium subjected to heat exchange is led out of the heat exchanger shell from the first heat medium outlet and the second heat medium outlet; the flue gas enters and exits the channel of the heat exchanger shell; and the collecting pipe is connected with each heat exchange branch pipe. The indirect heat exchanger is simple in structure, large in specific surface area, high in heat exchange efficiency and small in size, modular serial connection can be carried out according to the heat exchange temperature difference requirement, and the heat exchange requirements of various working conditions are met.

Description

Technical Field

[0001] The utility model belongs to the technical field of flue gas heat exchange, in particular to an indirect heat exchanger. Background Art

[0002] The flue gas heat exchanger is a device that uses a refrigerant or a heat medium to cool or heat the flue gas. It is widely used and has various forms. According to the principle, it is mainly divided into direct heat exchange and indirect heat exchange. The former is to make the flue gas directly contact with the refrigerant or the heat medium through a filler or a spray system to achieve the purpose of heating and cooling, while the latter is that the refrigerant and the heat medium are in the heat exchange coil, not in direct contact with the flue gas, and heat is transferred through the coil wall to absorb or provide heat to the flue gas side to achieve the purpose of heating and cooling.

[0003] Direct heat exchange is rarely used because it has many requirements on the properties of the refrigerant or heat medium and flue gas, as well as whether there is a chemical reaction between them. Indirect heat exchangers are widely used. The heat exchange efficiency of indirect heat exchangers is related to the specific surface area of ​​the heat exchanger. The larger the heat exchange area, the better the heat exchange effect, but the corresponding equipment volume is larger, the floor space is large, and the installation is inconvenient. In addition, there are many heat exchangers with uneven distribution of heat medium, resulting in poor heat exchange uniformity on the cross section of the heat exchanger, which leads to poor overall heat exchange efficiency. Utility Model Content

[0004] In order to solve all or part of the above problems, the utility model aims to provide an indirect heat exchanger with simple structure, large specific surface area, high heat exchange efficiency and small volume. At the same time, it can be modularly connected in series according to the heat exchange temperature difference requirements to meet the heat exchange requirements of various working conditions.

[0005] To achieve the above purpose, the utility model provides the following technical solution: an indirect heat exchanger, comprising:

[0006] Heat exchange branch pipe, the heat medium flows in the heat exchange branch pipe, transfers the heat to the outer wall of the heat exchange branch pipe, and contacts with the flue gas outside the heat exchange branch pipe to achieve heat exchange;

[0007] The manifold is used to connect the heat exchange branch pipes;

[0008] The heat exchanger shell has heat exchange branch pipes and manifolds arranged inside it;

[0009] Heat medium inlet 1 and heat medium inlet 2, through which heat medium enters the heat exchanger shell;

[0010] Heat medium outlet 1 and heat medium outlet 2. After heat exchange, the heat medium is discharged from the heat exchanger shell through the heat medium outlet 1 and the heat medium outlet 2.

[0011] Flue gas inlet and outlet, the passage for flue gas to enter and exit the heat exchanger shell;

[0012] The manifold is connected to each heat exchange branch pipe to achieve remixing and redistribution of the heat medium in the manifold.

[0013] As a preferred embodiment, a gap is provided on one side of the heat exchanger shell to which the manifold is parallel, and the size of the gap is no greater than 15 mm.

[0014] As a preferred embodiment, the heat exchange branch pipe is arranged as an oblique "V"-shaped elbow pipe, and the lowest point of the heat exchange branch pipe is offset from the symmetrical center line of the heat exchanger shell.

[0015] As a preferred embodiment, the connection position between the heat exchange branch and the manifold is at the bottom of the manifold, and heat medium flows into half of the connected heat exchange branch and flows out of the other half, and the heat exchange branches flowing into and out of the manifold are arranged in a 1-to-1 interval.

[0016] As a preferred embodiment, one end of the topmost and bottommost manifolds is a closed structure, and the other end extends out of the heat exchanger shell and is connected to the channel for the external heat medium to enter and exit the heat exchange system, while both ends of several middle manifolds are closed structures. After the heat medium is converged to the manifold through the heat exchange branch pipes, it flows out of the manifold through the outflow heat exchange branch pipes.

[0017] As a preferred embodiment, the heat exchange branch pipes and the manifold are both made of stainless steel, and the heat exchange branch pipes and the manifold are welded and connected with stainless steel welding rods.

[0018] As a preferred embodiment, the heat exchanger shell is provided with two heat medium flow inlets and two heat medium flow outlets. The heat exchange branch pipes and the manifold constitute a heat exchange system. When the heat exchange requirement is high, multiple heat exchange systems can be used in series.

[0019] Compared with the prior art, the technical effects and advantages of the utility model are as follows:

[0020] The indirect heat exchanger has a simple structure, a large specific surface area, a high heat exchange efficiency, and a small volume. At the same time, it can be modularly connected in series according to the heat exchange temperature difference requirements to meet the heat exchange requirements of various working conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the specific implementation methods of the utility model or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0022] Figure 1 It is a structural schematic diagram of an indirect heat exchanger device according to an embodiment of the utility model;

[0023] Figure 2 The flow channel diagram of the heat medium (or coolant) of the embodiment of the utility model is schematically shown;

[0024] Figure 3 The connection diagram between the manifold and the heat exchange branch pipes of the embodiment of the utility model is schematically shown;

[0025] Figure 4 The schematic diagram of the serial use of multi-stage heat exchangers in an embodiment of the utility model is shown schematically.

[0026] Description of reference numerals:

[0027] In the figure: 1. Heat exchange branch pipe; 2. Heat medium outlet 1; 3. Heat medium inlet 1; 4. Flue gas inlet and outlet; 5. Heat exchanger shell; 6. Heat medium inlet 2; 7. Heat medium outlet 2; 8. Converging pipe. DETAILED DESCRIPTION

[0028] In the following description, a large number of specific details are given to provide a more thorough understanding of the utility model. However, it is obvious to those skilled in the art that the utility model can be implemented without one or more of these details. In other examples, in order to avoid confusion with the utility model, some technical features known in the art are not described.

[0029] Unless otherwise defined, the directions of up, down, left, right, front, back, inside and outside involved in this document are based on the directions of up, down, left, right, front, back, inside and outside in the figures shown in the present utility model, and are explained here together.

[0030] The connection method can be bonding, welding, bolt connection, etc., depending on actual needs. Embodiment 1

[0031] See also Figures 1 to 3As shown, this embodiment includes a heat exchange branch pipe 1, which is set as an oblique "V"-shaped elbow pipe. The lowest point of the heat exchange branch pipe 1 is offset from the symmetrical center line of the heat exchanger shell 5. The connection position between the heat exchange branch pipe 1 and the manifold 8 is at the bottom of the manifold 8, and the heat medium flows into half of the connected heat exchange branch pipe 1, and the heat medium flows out of the other half, and the heat exchange branch pipes 1 flowing into and out of the manifold 8 are arranged in a 1-to-1 interval. The heat medium flows in the heat exchange branch pipe 1, conducts heat to the outer wall of the heat exchange branch pipe 1, and contacts with the flue gas outside the heat exchange branch pipe 1 to achieve heat exchange. The heat medium (or refrigerant) enters the manifold 8 at the bottom layer from the heat medium inlet 1 3 and the heat medium inlet 2 6, and then enters each heat exchange branch pipe 1, and then reaches the manifold 8 of the second stage. After merging and mixing in the manifold 8 of the second stage, the heat exchange branch pipe 1 of the outflow type enters the manifold 8 of the next upper stage, for example, Figure 2 As shown, the heat medium entering from the heat medium inlet 3 passes through ammckeig in sequence and then flows out from the heat medium outlet 2. The heat medium entering from the heat medium inlet 6 passes through nbldjfh in sequence and finally flows out from the heat medium outlet 7.

[0032] refer to Figure 3 , the manifold 8 is used to connect the heat exchange branch pipes 1. The number and position of the heat exchange branch pipes 1 compared to the manifold 8 are selected according to actual needs. One end of the manifold 8 at the top and bottom layers is a closed structure, and the other end extends out of the heat exchanger shell 5 and is connected to the channel of the external heat medium entering and exiting the heat exchange system, while both ends of the middle several manifolds 8 are closed structures. After the heat medium converges to the manifold 8 through the heat exchange branch pipes 1, it flows out of the manifold 8 through the outflowing heat exchange branch pipes 1.

[0033] The heat exchanger shell 5, the heat exchange branch pipe 1 and the manifold 8 are arranged inside the heat exchanger shell 5, and the manifold 8 has a gap on one side of the heat exchanger shell 5 parallel to the manifold 8, and the gap size is not greater than 15 mm.

[0034] Heat medium inlet 1 3 and heat medium inlet 2 6, the heat medium enters the heat exchanger shell 5 through heat medium inlet 1 3 and heat medium inlet 2 6, heat medium outlet 1 2 and heat medium outlet 2 7, and the heat medium after heat exchange is discharged from the heat exchanger shell 5 through heat medium outlet 1 2 and heat medium outlet 2 7.

[0035] The smoke inlet and outlet 4 is a passage for smoke to enter and exit the heat exchanger shell 5. The smoke inlet and outlet 4 can be connected to an external special ventilation device to provide power for the smoke. The smoke that needs to be heat exchanged enters through the smoke inlet. Due to the temperature difference between the smoke temperature and the surface temperature of the heat exchange branch pipe 1, heat exchange is carried out on the surface of the heat exchange branch pipe 1.

[0036] The manifold 8 is connected to each heat exchange branch pipe 1 to achieve remixing and redistribution of heat medium in the manifold 8. The heat exchange branch pipe 1 and the manifold 8 are both made of stainless steel, and the heat exchange branch pipe 1 and the manifold 8 are welded and connected using stainless steel welding rods.

[0037] The heat exchanger housing 5 is provided with two heat medium flow inlets and two heat medium flow outlets, the inlets are located at the bottom and the outlets are located at the top. Embodiment 2

[0038] refer to Figure 4 The heat exchange branch pipe 1 and the confluence pipe 8 constitute a heat exchange system. When the heat exchange requirement is high, multiple heat exchange systems can be used in series. The specific number is not based on the diagram and is selected according to actual needs.

[0039] How it works

[0040] In the indirect heat exchanger, during use, the heat medium (or cold medium) enters the bottom-level manifold 8 from the heat medium inlet 1 3 and the heat medium inlet 2 6, then enters each heat exchange branch pipe 1, and then reaches the second-level manifold 8. After the mixed flow is merged in the second-level manifold 8, the heat medium (or cold medium) enters the next-level manifold 8 from the outflow-type heat exchange branch pipe 1 of the manifold 8. For example, Figure 2 As shown, the heat medium entering from the heat medium inlet 3 passes through ammckeig in sequence and then flows out from the heat medium outlet 2. The heat medium entering from the heat medium inlet 6 passes through nbldjfh in sequence and finally flows out from the heat medium outlet 7. The schematic diagram of the inflow and outflow channels on the manifold 8 is shown in the attached figure. Figure 3 As shown, the inflow and outflow manifolds 8 are arranged one-to-one, and the flue gas that needs heat exchange enters from the flue gas inlet. Due to the temperature difference between the flue gas temperature and the surface temperature of the heat exchange branch pipe 1, heat exchange is performed on the surface of the heat exchange branch pipe 1 to cool or heat the flue gas. Then the flue gas flows out of the heat exchanger from the flue gas outlet. If the heat exchange intensity needs to be enhanced, multi-stage heat exchangers can be installed in series.

[0041] It should be noted that, in this article, relational terms such as one and two are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions. The sentence "includes an element defined by ... does not exclude the existence of other identical elements in the process, method, article or device including the element".

[0042] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An indirect heat exchanger, characterized in that: include, A heat exchange branch pipe (1), wherein a heat medium flows in the heat exchange branch pipe (1), conducts heat to the outer wall of the heat exchange branch pipe (1), and contacts the flue gas outside the heat exchange branch pipe (1), thereby achieving heat exchange; A manifold (8) used for connecting the heat exchange branch pipes (1); A heat exchanger shell (5), a heat exchange branch pipe (1) and a manifold (8) are arranged inside the shell; Heat medium inlet one (3) and heat medium inlet two (6), through which heat medium enters the heat exchanger shell (5); A heat medium outlet 1 (2) and a heat medium outlet 2 (7), wherein the heat medium after heat exchange is discharged from the heat exchanger housing (5) through the heat medium outlet 1 (2) and the heat medium outlet 2 (7); A flue gas inlet and outlet (4), a passage for flue gas to enter and exit the heat exchanger shell (5); The manifold (8) is connected to each heat exchange branch pipe (1), and remixing and redistribution of the heat medium is achieved in the manifold (8).

2. An indirect heat exchanger according to claim 1, characterized in that: The manifold (8) has a gap on one side of the heat exchanger shell (5) parallel to it, and the size of the gap is no greater than 15 mm.

3. An indirect heat exchanger according to claim 1, characterized in that: The heat exchange branch pipe (1) is arranged as an oblique "V"-shaped bend pipe, and the lowest point of the heat exchange branch pipe (1) is arranged offset from the symmetrical center line of the heat exchanger shell (5).

4. The indirect heat exchanger according to claim 1, characterized in that: The connection position between the heat exchange branch pipe (1) and the manifold (8) is at the bottom of the manifold (8), and heat medium flows into half of the connected heat exchange branch pipe (1), and heat medium flows out of the other half, and the heat exchange branch pipes (1) flowing into and out of the manifold (8) are arranged in a one-to-one interval.

5. The indirect heat exchanger according to claim 1, characterized in that: One end of the topmost and bottommost conduits (8) is a closed structure, and the other end extends out of the heat exchanger shell (5) and is connected to the channel for the external heat medium to enter and exit the heat exchange system, while both ends of the middle conduits (8) are closed structures. After the heat medium is converging to the conduit (8) through the heat exchange branch pipes (1), it flows out of the conduit (8) through the outflow heat exchange branch pipes (1).

6. The indirect heat exchanger according to claim 1, characterized in that: The heat exchange branch pipe (1) and the manifold (8) are both made of stainless steel, and the heat exchange branch pipe (1) and the manifold (8) are welded together using stainless steel welding rods.

7. The indirect heat exchanger according to claim 1, characterized in that: The heat exchanger shell (5) is provided with two heat medium flow inlets and two heat medium flow outlets. The heat exchange branch pipes (1) and the confluence pipe (8) form a heat exchange system. When the heat exchange requirement is high, multiple heat exchange systems can be used in series.

Images