Double-pipe combined double-pipe heat exchanger and control method thereof

Abstract

The application provides a double-pipeline combined double-pipe heat exchanger and a control method thereof. The double-pipe heat exchanger comprises an outer pipe, a first inner pipe, a second inner pipe, a water inlet pipe, a reversing valve, a water quality detector and a controller. The first inner pipe and the second inner pipe are arranged in parallel in the outer pipe. The water inlet pipe is connected to the inlets of the first inner pipe and the second inner pipe through the reversing valve. The outer pipe is used for passing refrigerant, and the water inlet pipe is used for passing cooling water. The water quality detector is arranged on the water inlet pipe and is used for monitoring the water quality of the cooling water. The corrosion resistance of the material of the second inner pipe is better than that of the material of the first inner pipe. The controller is electrically connected to the reversing valve and the water quality detector. According to the water quality of the unit cooling water, the inner pipe with corresponding corrosion resistance is selected to participate in heat exchange, so that the corrosion risk of the inner pipe is reduced, and the service life of the double-pipe heat exchanger is prolonged.

Description

Technical Field

[0001] This invention relates to the field of heat exchanger technology, specifically to a dual-pipeline combined shell-and-tube heat exchanger and its control method. Background Technology

[0002] In the field of shell-and-tube heat exchangers, different water intake environments can easily lead to varying corrosive media in the pipes. These changes in corrosive media cause the pipes to lose their ability to adjust and adapt, further resulting in corrosion penetration. Pipe corrosion penetration can easily cause the entire unit to fail, resulting in economic losses. This problem is prevalent in shell-and-tube heat exchangers and causes significant inconvenience to users. Summary of the Invention

[0003] In view of the shortcomings of the prior art, the present invention provides a shell-and-tube heat exchanger with dual pipeline combination and its control method, which can improve the adaptability of the shell-and-tube heat exchanger to corrosive environments.

[0004] To achieve the above objectives, according to one aspect of the present invention, a dual-pipe combination shell-and-tube heat exchanger is provided, comprising an outer tube, a first inner tube, a second inner tube, a water inlet pipe, a reversing valve, a water quality analyzer, and a controller;

[0005] The first inner pipe and the second inner pipe are arranged in parallel inside the outer pipe. The water inlet pipe is connected to the inlet of the first inner pipe and the second inner pipe through the reversing valve. The outer pipe is used to introduce refrigerant, and the water inlet pipe is used to introduce cooling water.

[0006] The water quality analyzer is installed on the inlet pipe to monitor the water quality of the cooling water. The corrosion resistance of the material of the second inner pipe is better than that of the material of the first inner pipe. The controller is electrically connected to the reversing valve and the water quality analyzer.

[0007] As an improvement of the present invention, the water quality analyzer monitors parameters including: pH value, iron ion concentration, ammonium ion concentration, chloride ion concentration, and flow rate.

[0008] As an improvement of the present invention, the flow direction of the refrigerant is opposite to the flow direction of the cooling water.

[0009] As an improvement of the present invention, both the first inner tube and the second inner tube are spiral tubes.

[0010] As an improvement of the present invention, both the first inner tube and the second inner tube are copper tubes.

[0011] As an improvement of the present invention, the inner tube is a spiral tube.

[0012] According to another aspect of the present invention, a control method for the above-described dual-pipeline combined shell-and-tube heat exchanger is provided, comprising the following steps:

[0013] Preset cooling water iron ion concentration a0, preset cooling water ammonium ion concentration b0, preset cooling water chloride ion concentration c0, preset cooling water flow rate v0;

[0014] Obtain the pH value of the cooling water. If pH ≤ 7 or pH > 9, connect the second inner pipe to the inlet pipe.

[0015] As an improvement of the present invention, if 7 < pH ≤ 9, then the real-time concentration a of iron ions in the cooling water is further obtained; if a > a0, the second inner tube is connected to the water inlet pipe.

[0016] As an improvement of the present invention, if a≤a0, then the real-time concentration b of ammonium ions in the cooling water is further obtained; if b>b0, the second inner tube is connected to the water inlet pipe.

[0017] As an improvement of the present invention, if b≤b0, then the real-time concentration c of chloride ions in the cooling water is further obtained; if c>c0, the second inner tube is connected to the water inlet pipe.

[0018] As an improvement of the present invention, if c≤c0, then the real-time flow rate v of the cooling water is further obtained; if v>v0, the second inner pipe is connected to the water inlet pipe; otherwise, the first inner pipe is connected to the water inlet pipe.

[0019] By applying the technical solution of this invention, the two inner tubes are made of materials with different corrosion resistance. According to the water quality of the cooling water, the inner tube with appropriate corrosion resistance is automatically selected to participate in heat exchange, thereby effectively reducing the risk of inner tube corrosion and thus improving the service life of the shell-and-tube heat exchanger. Attached Figure Description

[0020] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0021] Figure 1 This is a schematic diagram of the flow path of a shell-and-tube heat exchanger according to an embodiment of the present invention;

[0022] Figure 2 This is a schematic diagram of the structure of a shell-and-tube heat exchanger according to an embodiment of the present invention;

[0023] Figure 3 This is a flowchart of the control method according to an embodiment of the present invention;

[0024] in,

[0025] 1-Outer pipe; 2-First inner pipe; 3-Second inner pipe; 4-Inlet pipe; 5-Reversing valve; 6-Water quality analyzer. Detailed Implementation

[0026] The present invention will now be described in detail with reference to the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in the embodiments of this application can be combined with each other.

[0027] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of this application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0028] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0029] like Figure 1 and Figure 2 As shown, this embodiment of the invention provides a dual-pipeline combined shell-and-tube heat exchanger, including an outer tube 1, a first inner tube 2, a second inner tube 3, a water inlet pipe 4, a reversing valve 5, a water quality analyzer 6, and a controller.

[0030] The first inner pipe 2 and the second inner pipe 3 are connected in parallel inside the outer pipe 1. The water inlet pipe 3 is connected to the inlet of the first inner pipe 2 and the second inner pipe 3 through the reversing valve 4. The outer pipe 1 is used to introduce refrigerant, and the water inlet pipe 3 is used to introduce cooling water. The refrigerant and the cooling water can exchange heat.

[0031] The water quality detector 6 is installed on the inlet pipe 4 to monitor the water quality of the cooling water. The corrosion resistance of the material of the second inner pipe 3 is better than that of the material of the first inner pipe 2. The reversing valve 4 and the water quality detector 6 are both electrically connected to the controller. The controller can be set up independently or it can be the control system of the unit where the shell-and-tube heat exchanger is located.

[0032] Applying the technical solution of the present invention, the corrosion resistance of the material of the second inner tube 3 is better than that of the material of the first inner tube 2. The water quality detector 6 monitors the water quality of the cooling water in real time. When the corrosivity of the cooling water is high, the second inner tube 3 is selected for heat exchange, and when the corrosivity of the cooling water is low, the first inner tube 2 is selected for heat exchange.

[0033] As can be seen, the shell-and-tube heat exchanger of this application can achieve automatic switching and coordinated operation of the two inner tubes by monitoring the corrosiveness of the cooling water, which can effectively improve the service life of the shell-and-tube heat exchanger.

[0034] In this embodiment, both the first inner tube 2 and the second inner tube are made of copper. The first inner tube 2 is made of B10 copper-nickel alloy, and the second inner tube 3 is made of B30 copper-nickel alloy. The reversing valve 4 can be a three-way valve, with its three ports A, B, and C connected to the water inlet pipe 4, the first inner tube 2, and the second inner tube 3, respectively.

[0035] It should be noted that the multi-way reversing valve 4 can also be replaced by two electrically controlled valves, with the first inner tube 2 and the second inner tube 3 both controlled by one electrically controlled valve.

[0036] In this embodiment, in order to improve the heat exchange effect, both the first inner tube 2 and the second inner tube 3 are spiral tubes, and the flow direction of the refrigerant in the outer tube 1 is opposite to the flow direction of the cooling water in the inner tube.

[0037] In this embodiment, the water quality analyzer 6 is commercially available, and the monitoring parameters include, but are not limited to: pH value, iron ion concentration, ammonium ion concentration, chloride ion concentration, and flow rate, which can be adjusted according to the actual situation.

[0038] According to an embodiment of the present invention, a control method corresponding to the above-described shell-and-tube heat exchanger is also provided, which is described below in conjunction with... Figure 3 The specific control process will be explained.

[0039] 1. Preset cooling water iron ion (Fe) 3+ Concentration a0, preset cooling water ammonium ion (NH4+) 4+ The preset chloride ion (Cl-) concentration is b0, the preset chloride ion (Cl-) concentration in the cooling water is c0, and the preset cooling water flow rate is v0.

[0040] 2. Power on;

[0041] 3. Obtain the pH value of the cooling water. If pH ≤ 7 or pH > 9, directly use B30 copper pipe, that is, connect the AC port of the three-way valve, and the system exchanges heat through the second inner pipe 3. After running for a specific time, enter the shutdown confirmation process.

[0042] 4. If 7 < pH ≤ 9, then further obtain the real-time concentration 'a' of iron ions in the cooling water. If 'a' > 'a0', directly use B30 copper pipes. After running for a specific time, enter the shutdown confirmation process.

[0043] 5. If a≤a0, then obtain the real-time concentration b of ammonium ions in the cooling water. If b>b0, directly use B30 copper pipes. After running for a specific time, enter the shutdown confirmation process.

[0044] 6. If b≤b0, then obtain the real-time concentration c of chloride ions in the cooling water. If c>c0, directly use B30 copper pipes. After running for a specific time, enter the shutdown confirmation process.

[0045] 7. If c≤c0, then obtain the real-time flow rate v of the cooling water. If v>v0, directly use B30 copper pipe. After running for a specific time, enter the shutdown confirmation process.

[0046] 8. If v≤v0, then B10 copper pipe is used, that is, the AB ports of the three-way valve are connected, the system exchanges heat through the first inner pipe 2, and after running for a certain period of time, it enters the shutdown confirmation process;

[0047] 9. After entering the shutdown process, the system asks whether to shut down. If the user confirms the shutdown, the system shuts down; if the user does not shut down, the system returns to process 3.

[0048] As can be seen from the above description, the shell-and-tube heat exchanger of this application features dual water pipeline switching and can automatically adjust the operating pipeline according to the working conditions, thereby achieving intelligent processing. This solves the problem that the existing shell-and-tube heat exchangers cannot switch pipelines under different water environments, resulting in irreversible damage to the pipelines in highly corrosive environments, thus expanding the application range of the unit.

[0049] In the description of this invention, it should be understood that the orientations or positional relationships indicated by terms such as "center," "front," "back," "up," "down," "left," "right," "horizontal," "vertical," "horizontal," and "top," "bottom," etc., are generally based on the orientations or positional relationships shown in the accompanying drawings and are only for the convenience of describing this invention and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as limiting the scope of protection of this invention; the directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0050] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0051] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore should not be construed as limiting the scope of protection of this invention.

[0052] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A control method for a dual-pipeline combined shell-and-tube heat exchanger, characterized in that, The shell-and-tube heat exchanger includes an outer tube (1), a first inner tube (2), a second inner tube (3), an inlet pipe (4), a reversing valve (5), a water quality analyzer (6), and a controller; the water quality analyzer (6) monitors parameters including pH value and iron ion concentration; The first inner tube (2) and the second inner tube (3) are arranged in parallel inside the outer tube (1). The water inlet pipe (4) is connected to the inlet of the first inner tube (2) and the second inner tube (3) through the reversing valve (5). The outer tube (1) is used to introduce refrigerant, and the water inlet pipe (4) is used to introduce cooling water. The flow direction of the refrigerant is opposite to the flow direction of the cooling water. The water quality detector (6) is installed on the inlet pipe (4) to monitor the water quality of the cooling water. The corrosion resistance of the material of the second inner pipe (3) is better than that of the material of the first inner pipe (2). The controller is electrically connected to the reversing valve (5) and the water quality detector (6). The control method includes the following steps: Obtain the pH value of the cooling water. If pH ≤ 7 or pH > 9, connect the second inner tube (3) to the inlet pipe (4); if 7 < pH ≤ 9, then further obtain the real-time concentration a of iron ions in the cooling water.

2. The control method for the dual-pipeline combined shell-and-tube heat exchanger according to claim 1, characterized in that: Both the first inner tube (2) and the second inner tube (3) are spiral tubes.

3. The control method for the dual-pipeline combined shell-and-tube heat exchanger according to claim 1, characterized in that: Both the first inner tube (2) and the second inner tube (3) are copper tubes.

4. The control method for the dual-pipeline combined shell-and-tube heat exchanger according to claim 1, characterized in that: The water quality analyzer (6) also monitors parameters including ammonium ion concentration, chloride ion concentration, and flow rate; Preset cooling water iron ion concentration a0, preset cooling water ammonium ion concentration b0, preset cooling water chloride ion concentration c0, preset cooling water flow rate v0; If a > a0, the second inner pipe (3) is connected to the water inlet pipe (4).

5. The control method for the dual-pipeline combined shell-and-tube heat exchanger according to claim 4, characterized in that: If a≤a0, then the real-time concentration b of ammonium ions in the cooling water is obtained. If b>b0, the second inner tube (3) is connected to the inlet pipe (4).

6. The control method for the dual-pipeline combined shell-and-tube heat exchanger according to claim 5, characterized in that: If b≤b0, then the real-time concentration c of chloride ions in the cooling water is obtained. If c>c0, the second inner tube (3) is connected to the inlet pipe (4).

7. The control method for the dual-pipeline combined shell-and-tube heat exchanger according to claim 6, characterized in that: If c≤c0, then the real-time flow rate v of the cooling water is obtained. If v>v0, the second inner pipe (3) is connected to the water inlet pipe (4). Otherwise, the first inner pipe (2) is connected to the water inlet pipe (4).

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