Counter-flow type multi-stage heat exchange system

Abstract

The utility model discloses a reverse flow type multi-stage heat exchange system which comprises a first-stage heat exchange unit, a second-stage heat exchange unit and a third-stage heat exchange unit, and medium inlets and outlets and heat exchange inlets and outlets of the three heat exchange units are respectively communicated. A first-stage heat exchange inlet is formed in the first-stage heat exchange unit and is connected with the first-stage heat exchange unit through a conical diffuser and a honeycomb guide plate; a second-stage heat exchange inlet is formed in the second-stage heat exchange unit, and the second-stage heat exchange inlet is connected with the second-stage heat exchange unit through a Venturi nozzle; a plurality of first-stage heat exchange pipes are arranged in the first-stage heat exchange unit and are corrugated pipes, a plurality of second-stage heat exchange pipes are arranged in the second-stage heat exchange unit and are spiral fluted pipes, and a plurality of third-stage heat exchange pipes are arranged in the third-stage heat exchange unit and are finned pipes. Cold fluid and hot fluid are arranged in a cross countercurrent mode, the device is efficient, flexible, high in adaptability, simple in structure, convenient to maintain, low in cost and capable of achieving low-temperature waste heat recovery, and comprehensive energy efficiency is greatly improved.

Description

Technical Field

[0001] This utility model relates to the field of heat exchanger technology, and in particular to a counter-flow multi-stage heat exchange system. Background Technology

[0002] Traditional single-stage tubular heat exchangers exhibit low heat exchange efficiency when the temperature difference between hot and cold fluids is small or the flow rate is large. Single-stage heat exchange is insufficient to meet the requirements of high-efficiency heat transfer and is prone to clogging when handling high-viscosity fluids containing impurities. Although existing technologies include multi-stage heat exchange designs, they generally suffer from uneven heat distribution between stages, complex structures, difficult maintenance, and high costs. Therefore, there is an urgent need for a highly efficient, flexible, and adaptable multi-stage tubular heat exchange system. Utility Model Content

[0003] The technical problem to be solved by this utility model is to provide a counter-flow multi-stage heat exchange system, which aims to solve the technical problems existing in the prior art, such as limited single-stage heat exchange efficiency, poor fluid adaptability, uneven heat distribution between stages, complex structure, difficult maintenance, and high cost.

[0004] The technical solution of this utility model is: a counter-current multi-stage heat exchange system, including a primary heat exchange unit, a secondary heat exchange unit, and a tertiary heat exchange unit. The inlet and outlet of the primary, secondary, and tertiary heat exchange units are connected, and the inlet and outlet of the heat exchange units are also connected. The primary heat exchange unit is provided with a primary heat exchange inlet, which is connected to the primary heat exchange unit via a conical diffuser and a honeycomb guide plate. The secondary heat exchange unit is provided with a secondary heat exchange inlet, which is connected to the secondary heat exchange unit via a Venturi nozzle. The primary heat exchange unit contains a plurality of primary heat exchange tubes, which are corrugated tubes. The secondary heat exchange unit contains a plurality of secondary heat exchange tubes, which are spiral grooved tubes. The tertiary heat exchange unit contains a plurality of tertiary heat exchange tubes, which are finned tubes.

[0005] Furthermore, in this utility model, the primary heat exchange unit is provided with a primary medium inlet and a primary medium outlet, the secondary heat exchange unit is provided with a secondary medium inlet and a secondary medium outlet, and the tertiary heat exchange unit is provided with a tertiary medium inlet and a tertiary medium outlet. The tertiary medium outlet is connected to the secondary medium inlet, and the secondary medium outlet is connected to the primary medium inlet. The medium enters from the tertiary medium inlet and flows out from the primary medium outlet.

[0006] Furthermore, in this utility model, the primary heat exchange unit is provided with a primary heat exchange outlet, which is connected to the secondary heat exchange inlet; the secondary heat exchange unit is provided with a secondary heat exchange outlet, and the tertiary heat exchange unit is provided with a tertiary heat exchange inlet and a tertiary heat exchange outlet, with the secondary heat exchange outlet connected to the tertiary heat exchange inlet, and the heat exchange material enters from the primary heat exchange inlet and flows out from the tertiary heat exchange outlet.

[0007] Furthermore, in this utility model, several of the primary heat exchange tubes are arranged in an equilateral triangle, the primary heat exchange tubes are made of 316L stainless steel, and the inner wall of the primary heat exchange tubes is provided with a silicon carbide wear-resistant coating.

[0008] Furthermore, in this utility model, several of the secondary heat exchange tubes are arranged in a square, the secondary heat exchange tubes are made of copper-nickel alloy, and the inner wall of the secondary heat exchange tubes has a spirally arranged V-shaped groove.

[0009] Furthermore, in this utility model, several of the three-stage heat exchange tubes are arranged in parallel, the three-stage heat exchange tubes are aluminum-magnesium alloy finned tubes, and the fins of the three-stage heat exchange tubes are serrated fins.

[0010] Furthermore, the primary medium outlet of this utility model is connected to a waste heat recovery device, the waste heat recovery device is provided with an air preheating channel, and the waste heat recovery device is provided with an air inlet and an air outlet that are connected to the air preheating channel.

[0011] Compared with the prior art, this utility model has the following advantages: The heat exchange system of this utility model adopts a multi-stage counter-current + series combination layout, which can maximize the utilization rate of temperature difference, improve the overall heat transfer coefficient, and greatly improve the heat exchange efficiency; Each heat exchange unit adopts a differentiated structure, such as corrugated tube, spiral grooved tube, and finned tube, which can enhance turbulence and prevent clogging, enhance heat transfer efficiency, and have good fluid adaptability; When the entire heat exchange system is working, the hot and cold fluids adopt a cross-counter-current arrangement, which is highly efficient, flexible and adaptable, simple in structure, convenient to maintain and low in cost, and can also realize low-temperature waste heat recovery, greatly improving the overall energy efficiency. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the structure of this utility model;

[0013] Figure 2 This is a schematic diagram of the layout of the primary heat exchange tube described in this utility model;

[0014] Figure 3 This is a schematic diagram of the specific structure of the primary heat exchange tube described in this utility model;

[0015] Figure 4 This is a schematic diagram of the layout of the secondary heat exchange tubes described in this utility model;

[0016] Figure 5 This is a schematic diagram of the specific structure of the secondary heat exchange tube described in this utility model.

[0017] The components are as follows: 1. Primary heat exchange unit; 1a. Primary medium inlet; 1b. Primary medium outlet; 1c. Primary heat exchange inlet; 1d. Primary heat exchange outlet; 1e. Primary heat exchange tube; 2. Secondary heat exchange unit; 2a. Secondary medium inlet; 2b. Secondary medium outlet; 2c. Secondary heat exchange inlet; 2d. Secondary heat exchange outlet; 2e. Secondary heat exchange tube; 3. Tertiary heat exchange unit; 3a. Tertiary medium inlet; 3b. Tertiary medium outlet; 3c. Tertiary heat exchange inlet; 3d. Tertiary heat exchange outlet; 3e. Tertiary heat exchange tube; 4. Conical diffuser; 5. Honeycomb guide plate; 6. Venturi nozzle; 7. V-groove. Detailed Implementation

[0018] The specific embodiments of this utility model are described in detail below with reference to the accompanying drawings.

[0019] Example:

[0020] The accompanying drawings illustrate a specific embodiment of the counter-current multi-stage heat exchange system of this utility model. (Refer to...) Figure 1 It mainly includes a primary heat exchange unit 1, a secondary heat exchange unit 2, and a tertiary heat exchange unit 3. The inlet and outlet of the primary heat exchange unit 1, the secondary heat exchange unit 2, and the tertiary heat exchange unit 3 are connected, and the heat exchange inlet and outlet of the primary heat exchange unit 1, the secondary heat exchange unit 2, and the tertiary heat exchange unit 3 are connected.

[0021] Specifically, the first-stage heat exchange unit 1 has a first-stage medium inlet 1a and a first-stage medium outlet 1b at both ends, the second-stage heat exchange unit 2 has a second-stage medium inlet 2a and a second-stage medium outlet 2b at both ends, and the third-stage heat exchange unit 3 has a third-stage medium inlet 3a and a third-stage medium outlet 3b at both ends. The third-stage medium outlet 3b is connected to the second-stage medium inlet 2a, and the second-stage medium outlet 2b is connected to the first-stage medium inlet 1a. The medium enters from the third-stage medium inlet 3a and flows out from the first-stage medium outlet 1b.

[0022] The primary heat exchange unit 1 has a primary heat exchange inlet 1c at the bottom and a primary heat exchange outlet 1d at the top. The secondary heat exchange unit 2 has a secondary heat exchange inlet 2c at the bottom and a secondary heat exchange outlet 2d at the top. The tertiary heat exchange unit 3 has a tertiary heat exchange inlet 3c at the bottom and a tertiary heat exchange outlet 3d at the top. The primary heat exchange inlet 1c is connected to the primary heat exchange unit 1 through a conical diffuser 4 and a honeycomb guide plate 5, and the primary heat exchange outlet 1d is connected to the secondary heat exchange inlet 2c. The secondary heat exchange inlet 2c is connected to the secondary heat exchange unit 2 through a venturi nozzle 6, and the secondary heat exchange outlet 2d is connected to the tertiary heat exchange inlet 3c. The heat exchange material enters from the primary heat exchange inlet 1c and flows out from the tertiary heat exchange outlet 3d.

[0023] The primary heat exchange unit 1 contains several primary heat exchange tubes 1e, with both ends of each tube connected to the primary medium inlet 1a and the primary medium outlet 1b, respectively. Combined with... Figure 2 , Figure 3 Several primary heat exchange tubes 1e are arranged in an equilateral triangle. The primary heat exchange tubes 1e are corrugated and made of 316L stainless steel, which can enhance turbulence and prevent clogging, and are suitable for high viscosity or particulate fluids. The inner wall of the primary heat exchange tubes 1e is coated with a silicon carbide wear-resistant coating, which is wear-resistant and can reduce the scaling rate.

[0024] The conical diffuser 4 and honeycomb guide plate 5 installed at the primary heat exchange inlet 1c can effectively prevent the fluid from directly impacting the primary heat exchange tube 1e.

[0025] The secondary heat exchange unit 2 is equipped with several secondary heat exchange tubes 2e, with both ends of each tube connected to the secondary medium inlet 2a and the secondary medium outlet 2b, respectively. Figure 4 , Figure 5 Several secondary heat exchange tubes 2e are arranged in a square. The secondary heat exchange tubes 2e are spiral grooved tubes made of copper-nickel alloy. The inner wall of the secondary heat exchange tubes 2e has spirally arranged V-shaped grooves 7, which can enhance turbulence and improve heat transfer efficiency.

[0026] The Venturi nozzle 6 installed at the inlet 2c of the secondary heat exchanger can accelerate fluid flow and increase the flow rate at the inlet.

[0027] The three-stage heat exchange unit 3 contains several three-stage heat exchange tubes 3e, with both ends of each tube connected to the three-stage medium inlet 3a and the three-stage medium outlet 3b, respectively. The tubes 3e are arranged side-by-side and are made of aluminum-magnesium alloy finned tubes. The fins of the tubes 3e are serrated, which, compared to traditional straight fins, more effectively promote fluid mixing and convection on the fin surface, especially under low flow rate conditions.

[0028] In addition, not shown, the primary medium outlet 1b is also connected to a waste heat recovery device. This device includes an air preheating channel, an air inlet, and an air outlet connected to the preheating channel. Air enters the preheating channel through the air inlet, is preheated, and then exits through the air outlet. A pipe for the flow of the medium can be installed within the preheating channel of the waste heat recovery device. The medium flows into the pipe and exchanges heat with the air in the preheating channel, raising the temperature of the low-temperature air, achieving waste heat recovery, and improving overall energy efficiency.

[0029] In the specific operation of the heat exchange system of this invention, the hot fluid enters from the tertiary medium inlet 3a, flows through the tertiary medium outlet 3b, the secondary medium inlet 2a, the secondary medium outlet 2b, and the primary medium inlet 1a, and exits from the primary medium outlet 1b. The cold fluid enters from the primary heat exchange inlet 1c, flows through the primary heat exchange outlet 1d, the secondary heat exchange inlet 2c, the secondary heat exchange outlet 2d, and the tertiary heat exchange inlet 3c, and exits from the tertiary heat exchange outlet 3d. The hot and cold fluids flow in opposite directions, maximizing the utilization of temperature difference, improving the overall heat transfer coefficient, and significantly enhancing heat exchange efficiency. The waste heat recovery device at the primary medium outlet 1b can also utilize the waste heat of the hot fluid to heat the air, raising the temperature of the low-temperature air for use in boilers or drying equipment, greatly improving the overall energy efficiency of the system.

[0030] Of course, the above embodiments are only for illustrating the technical concept and features of this utility model, and their purpose is to enable those skilled in the art to understand the content of this utility model and implement it accordingly. They should not be used to limit the protection scope of this utility model. All modifications made in accordance with the spirit and essence of the main technical solution of this utility model should be covered within the protection scope of this utility model.

Claims

1. A counter-current multi-stage heat exchange system, characterized in that: It includes a primary heat exchange unit (1), a secondary heat exchange unit (2), and a tertiary heat exchange unit (3). The inlet and outlet of the primary heat exchange unit (1), the secondary heat exchange unit (2), and the tertiary heat exchange unit (3) are connected, and the inlet and outlet of the heat exchange unit (1), the secondary heat exchange unit (2), and the tertiary heat exchange unit (3) are connected. The primary heat exchange unit (1) is provided with a primary heat exchange inlet (1c), which is connected to the primary heat exchange unit (1) through a conical diffuser (4) and a honeycomb guide plate (5). The secondary heat exchange unit (2) is provided with a secondary heat exchange inlet (2c), which is connected to the secondary heat exchange unit (2) through a Venturi nozzle (6); the primary heat exchange unit (1) is provided with a plurality of primary heat exchange tubes (1e), which are corrugated tubes; the secondary heat exchange unit (2) is provided with a plurality of secondary heat exchange tubes (2e), which are spiral grooved tubes; the tertiary heat exchange unit (3) is provided with a plurality of tertiary heat exchange tubes (3e), which are finned tubes.

2. The counter-current multi-stage heat exchange system according to claim 1, characterized in that: The primary heat exchange unit (1) is provided with a primary medium inlet (1a) and a primary medium outlet (1b). The secondary heat exchange unit (2) is provided with a secondary medium inlet (2a) and a secondary medium outlet (2b). The tertiary heat exchange unit (3) is provided with a tertiary medium inlet (3a) and a tertiary medium outlet (3b). The tertiary medium outlet (3b) is connected to the secondary medium inlet (2a), and the secondary medium outlet (2b) is connected to the primary medium inlet (1a). The medium enters from the tertiary medium inlet (3a) and flows out from the primary medium outlet (1b).

3. The counter-current multi-stage heat exchange system according to claim 2, characterized in that: The primary heat exchange unit (1) is provided with a primary heat exchange outlet (1d), which is connected to the secondary heat exchange inlet (2c); the secondary heat exchange unit (2) is provided with a secondary heat exchange outlet (2d); the tertiary heat exchange unit (3) is provided with a tertiary heat exchange inlet (3c) and a tertiary heat exchange outlet (3d), which is connected to the tertiary heat exchange inlet (3c); the heat exchange material enters from the primary heat exchange inlet (1c) and flows out from the tertiary heat exchange outlet (3d).

4. The counter-current multi-stage heat exchange system according to claim 1, characterized in that: The primary heat exchange tubes (1e) are arranged in an equilateral triangle. The primary heat exchange tubes (1e) are made of 316L stainless steel and the inner wall of the primary heat exchange tubes (1e) is provided with a silicon carbide wear-resistant coating.

5. The counter-current multi-stage heat exchange system according to claim 1, characterized in that: Several of the secondary heat exchange tubes (2e) are arranged in a square. The secondary heat exchange tubes (2e) are made of copper-nickel alloy. The inner wall of the secondary heat exchange tubes (2e) has a spirally arranged V-shaped groove (7).

6. The counter-current multi-stage heat exchange system according to claim 1, characterized in that: Several of the three-stage heat exchange tubes (3e) are arranged side by side. The three-stage heat exchange tubes (3e) are aluminum-magnesium alloy finned tubes, and the fins of the three-stage heat exchange tubes (3e) are serrated fins.

7. A counter-current multi-stage heat exchange system according to claim 2, characterized in that: The primary medium outlet (1b) is connected to a waste heat recovery device, which has an air preheating channel and an air inlet and an air outlet that are connected to the air preheating channel.

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