Heat exchanger for triple-effect evaporator

Abstract

The heat exchanger comprises a plurality of heat exchange units which are connected in series, each heat exchange unit comprises a hollow shell, a flow channel is arranged in the shell, a plurality of liquid cooling pipes are arranged in the flow channel, and an inlet used for receiving heat exchange liquid and an outlet used for discharging the heat exchange liquid are formed in the outer portion of the shell. And the inlets and the outlets of the adjacent heat exchange units are communicated.

Description

Technical Field

[0001] This utility model is a heat exchanger for a triple-effect evaporator. Background Technology

[0002] Triple-effect countercurrent evaporation technology is widely used in industries such as chemical, pharmaceutical, and food processing, and is particularly suitable for liquid concentration and wastewater treatment processes. This system typically consists of three evaporation units connected in series, achieving cascaded energy utilization through a multi-stage steam heat recovery mechanism, effectively reducing energy consumption. The heat exchanger, as the key device connecting the various effects, directly determines the overall system's energy efficiency and operational stability through its heat exchange efficiency, structural stability, and anti-fouling capabilities.

[0003] In existing triple-effect evaporator systems, plate heat exchangers are widely used for heat exchange between alkaline solutions, especially in the first effect, where the heat exchange between high-concentration (50%) and medium-concentration (40%) alkaline solutions is particularly critical. However, due to their structural characteristics and narrow internal channels, plate heat exchangers are prone to scaling and blockage after prolonged operation due to the precipitation of high-concentration alkaline solutions or the adhesion of impurities, severely affecting heat transfer efficiency. As heat exchange performance declines, system power consumption increases significantly, leading to higher operating costs. Furthermore, frequent cleaning also increases maintenance burdens and the risk of downtime.

[0004] More seriously, existing plate heat exchanger structures struggle to achieve effective counter-current flow control. Their sealing relies on clamping mechanisms, which can lead to gasket aging and fluid leakage after long-term operation, posing certain safety hazards. Therefore, existing plate heat exchanger technology is no longer sufficient to meet the requirements of continuous industrial operation and low energy consumption in addressing scaling, unstable sealing, and reduced heat exchange efficiency during heat exchange in high-concentration alkaline solutions.

[0005] Based on the above problems, there is an urgent need for a new type of heat exchanger that can effectively reduce the risk of scaling, improve heat transfer efficiency, enhance sealing reliability, and be suitable for industrial environments where triple-effect evaporators operate under high loads and long-term continuous operation. Utility Model Content:

[0006] The purpose of this invention is to overcome the shortcomings of the prior art and provide a heat exchanger for a triple-effect evaporator.

[0007] A heat exchanger for a triple-effect evaporator includes multiple heat exchange units connected in series. Each heat exchange unit includes a hollow shell with a flow channel inside and multiple liquid-cooled pipes inside the flow channel. The shell has an inlet for receiving heat exchange liquid and an outlet for discharging heat exchange liquid outside. The inlets and outlets of adjacent heat exchange units are connected.

[0008] Furthermore, the housing is a straight tube with end plates at both ends, and the liquid cooling tube is fixed to the end plates at both ends.

[0009] Furthermore, the liquid cooling pipe is arranged axially along the shell.

[0010] Furthermore, the housing is located inside the end plates, and both end plates have sealing caps on their outer sides.

[0011] Furthermore, the flow channel of the shell is provided with multiple baffles, and the baffles are provided with a predetermined angle greater than zero between them and the axis.

[0012] Furthermore, the baffles are located near the inner wall of the flow channel, and multiple baffles are arranged in an alternating manner.

[0013] Furthermore, the multiple baffles are divided into multiple groups, with each group of baffles spaced apart along a straight line parallel to the axis, and the baffles from different groups are staggered.

[0014] Furthermore, a fixing rod is installed between each set of baffles, and the fixing rod is located inside the flow channel.

[0015] Beneficial effects: Compared with the prior art, the present invention has the following advantages:

[0016] This invention significantly improves the continuity of the heat exchange process and the system integration by employing a structure of multiple heat exchange units connected in series. Compared to traditional single-stage heat exchangers, this structure can adapt to more complex heat load changes and facilitates the expansion of the number of modules as needed, meeting the configuration requirements of triple-effect evaporator systems of different sizes. Its overall system structure is simple, suitable for standardized industrial design and assembly, and facilitates later maintenance and replacement.

[0017] The internal liquid-cooled tubes of the heat exchanger are evenly arranged along the axial direction of the shell and fixed at both ends by end plates, achieving stable support and uniform flow guidance. This design not only improves the uniformity of heat exchange but also enhances the vibration resistance of the mechanical structure, making it particularly suitable for continuous operation environments with high flow rates and high pressures. Simultaneously, the straight-tube shell and end-cap sealing structure effectively prevent heat exchange medium leakage, improving the system's sealing reliability and operational safety.

[0018] By incorporating multiple sets of angle-optimized baffles within the casing and arranging them in a staggered, grouped manner, the fluid path is effectively disturbed, breaking the laminar flow structure and enhancing turbulence, thereby significantly improving the convective heat transfer effect between the fluid and the liquid cooling pipes. The introduction of fixing rods further strengthens the stability of the baffle structure, preventing loosening or displacement during operation and extending its service life.

[0019] Furthermore, the structural design of this utility model takes into account multiple balances between thermal efficiency, pressure loss, anti-fouling and mechanical strength. Through reasonable flow channel organization and thermal field control, it improves the overall energy efficiency ratio and operating economy of the equipment. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the heat exchanger as a whole;

[0021] Figure 2 yes Figure 1 A magnified view of a section at point A in the middle;

[0022] Figure 3 yes Figure 1 A magnified view of a section at point B in the middle;

[0023] In the diagram, 1 is the inlet, 2 is the shell, 3 is the outlet, 4 is the end cap, 5 is the liquid cooling pipe, 6 is the fixing rod, and 7 is the baffle. Detailed Implementation

[0024] To enhance understanding of this utility model, the present utility model will be further described in detail below with reference to the embodiments and accompanying drawings. These embodiments are only used to explain the present utility model and do not constitute a limitation on the scope of protection of the present utility model.

[0025] A heat exchanger for a triple-effect evaporator includes multiple heat exchange units connected in series. Each heat exchange unit includes a hollow shell 2, with a flow channel inside the shell 2 and multiple liquid cooling pipes 5 inside the flow channel. The shell 2 has an inlet 1 for receiving heat exchange liquid and an outlet 3 for discharging heat exchange liquid outside the shell 2. The inlet 1 and outlet 3 of adjacent heat exchange units are connected.

[0026] This embodiment incorporates multiple heat exchange units connected in series within a triple-effect evaporator, allowing the heat exchange liquid to flow sequentially through each unit, achieving a continuous heat exchange process. Each heat exchange unit contains liquid-cooled pipes 5, distributed within flow channels inside the shell 2. When the heat exchange liquid flows in from the inlet 1 outside the shell 2, heat exchange occurs between it and the liquid-cooled pipes 5 within the flow channels, and it is then discharged from the outlet 3. Simultaneously, the inlets 1 and outlets 3 of adjacent units are connected, ensuring smooth flow of the heat exchange liquid throughout the system, thereby improving overall heat exchange efficiency. This design simplifies the layout of the heat exchange system and enhances operational continuity and stability.

[0027] The heat exchanger is designed with multiple heat exchange units connected in series to form a continuous heat exchange path, making the heat exchange process more stable and efficient. Each heat exchange unit achieves efficient heat transfer through liquid-cooled tubes 5, which can effectively reduce energy consumption and improve the overall thermal efficiency of the triple-effect evaporator. At the same time, the series structure reduces the complexity of intermediate connections, which helps to simplify the installation and maintenance process. In addition, the control and management of each unit during system operation is more flexible and can adapt to various operating conditions and load changes.

[0028] In one possible implementation, the housing 2 is a straight tube with end plates at both ends, and the liquid cooling tube 5 is fixed at both ends to the end plates.

[0029] This embodiment employs a straight pipe structure to ensure that the fluid flow direction inside the shell 2 is aligned with the axis of the shell 2, which facilitates the formation of a stable flow field. The end plates at the ports not only seal both ends of the shell 2 but also provide fixed support for the liquid cooling pipes 5, ensuring that the liquid cooling pipes 5 do not experience axial displacement or swaying during flow, thereby improving heat exchange efficiency and extending equipment life.

[0030] This structure is simple and reliable, facilitating manufacturing and assembly. The end plate fixing of the liquid-cooled tubes 5 enhances the mechanical stability and pressure resistance of the entire heat exchange unit, making it suitable for continuous operation under high-intensity conditions. Simultaneously, this configuration improves structural sealing and reduces operational risks.

[0031] In one possible implementation, the liquid cooling pipe 5 is arranged axially along the housing 2.

[0032] The liquid cooling pipe 5 is arranged along the axial direction of the shell 2, allowing the hot fluid in the flow channel to exchange heat with the liquid cooling pipe 5 over a long distance. This arrangement increases the effective heat exchange length, enhances the heat conduction path, and improves the uniformity and efficiency of heat exchange.

[0033] Axial alignment reduces fluid turbulence interference, maintains a smooth and continuous heat exchange process, reduces pressure drop, and improves system operating efficiency and reliability. This design also optimizes internal structural compactness, saves space, and facilitates overall heat exchanger integration and layout.

[0034] In one possible implementation, the housing 2 is located inside the end plate, and both end plates are provided with sealing heads 4 on their outer sides.

[0035] End plates are placed at both ends of the shell 2, forming the flow channel boundary structure. End caps 4 are positioned outside the end plates to provide a seal, preventing fluid leakage. End caps 4 can withstand working pressure, ensuring stable internal liquid operation. The shell 2, end plates, and end caps 4 form a complete closed structure, enabling directional flow of the heat exchange fluid.

[0036] By installing end caps 4 on the outer side of the end plates, the sealing performance of the system is effectively improved, preventing safety risks caused by leakage of high-temperature and high-pressure fluids. This structure enhances the overall mechanical strength and contributes to the long-term stable operation of the system.

[0037] In one possible implementation, the flow channel of the housing 2 is provided with a plurality of baffles 7, and the baffles 7 are provided with a predetermined angle greater than zero between them and the axis.

[0038] After the fluid enters the flow channel of the shell 2, it undergoes a deflection motion under the guidance of the baffle 7, creating disturbance and increasing the contact time and contact area between the fluid and the surface of the liquid cooling pipe 5, thereby improving the heat transfer efficiency. The tilt angle of the baffle 7 causes the fluid to flow along a spiral or deflected path, preventing local stagnation.

[0039] This structure significantly enhances the fluid turbulence on the internal heat exchange surfaces, increases the heat transfer rate, effectively reduces thermal resistance, and improves the response speed and efficiency of the heat exchange system. It also inhibits scale buildup and extends service life.

[0040] In one possible implementation, the baffle 7 is disposed near the inner wall of the flow channel, and multiple baffles 7 are arranged alternately.

[0041] The baffles 7 are arranged near the inner wall of the flow channel to effectively control the flow path in the boundary area. The staggered arrangement creates multi-directional turbulence, which complicates the flow path of the hot fluid inside the shell 2, increases the heat exchange opportunity with the liquid cooling pipe 5, and breaks the laminar flow structure.

[0042] The staggered arrangement improves fluid turbulence and heat flow uniformity, enhancing the local heat transfer coefficient, making it particularly suitable for high-viscosity or easily fouling media. It also strengthens the fluid's scouring force on the pipe walls, effectively slowing down fouling buildup and increasing cleaning cycles and equipment durability.

[0043] In one possible implementation, the plurality of baffles 7 are divided into multiple groups, with each group of baffles 7 arranged at intervals along a straight line parallel to the axis, and the baffles 7 of different groups are arranged alternately.

[0044] The baffles 7 are evenly distributed along the axial direction in groups, with the baffles 7 arranged in a straight line within each group. The groups are staggered to form a layered disturbance structure. This arrangement enhances the complexity of the flow path, causing significant disturbance to the fluid after passing through each group.

[0045] The structure, arranged in groups and staggered configurations, achieves multi-level fluid disturbance, resulting in a more dispersed heat flow field and improved heat transfer uniformity. Simultaneously, it avoids local short circuits or dead zones, effectively extending the heat flow path and enhancing heat exchange efficiency.

[0046] In one possible implementation, a fixing rod 6 is provided between each set of baffles 7, and the fixing rod 6 is disposed in the flow channel.

[0047] Fixing rods 6 are installed between the 7 sets of baffles to firmly hold each baffle 7 in its designated position, preventing displacement or loosening of the baffles 7 due to fluid impact or long-term operation. The fixing rods 6 are located in the flow channel inside the housing 2, serving to reinforce the structure and guide the flow.

[0048] The installation of the fixing rod 6 significantly improves structural stability and prevents the baffle plate 7 from falling off, causing flow blockage or a decrease in heat exchange performance. This ensures long-term safe operation of the equipment, reduces maintenance frequency, and is particularly suitable for high-frequency or high-flow-rate systems.

[0049] Working Principle: The core structure of this heat exchanger consists of multiple heat exchange units connected in series. Each unit has a hollow shell 2, axially arranged liquid-cooled pipes 5, an internal flow channel structure, and a heat exchange fluid channel with an inlet 1 and an outlet 3, aiming to achieve a highly efficient, stable, and scalable heat exchange process. Its working mechanism can be systematically explained from the following aspects:

[0050] Multiple heat exchange units are connected sequentially through their inlet 1 and outlet 3, forming a continuous passage. This allows the heat exchange medium to flow continuously through multiple shells 2 along a predetermined path, exchanging heat with the internal liquid cooling pipes 5 in sequence. This structure not only expands the heat exchange area but also facilitates the control of the temperature gradient at each stage, thereby improving the overall heat exchange efficiency.

[0051] Each heat exchange unit adopts a straight-tube shell structure 2, with internal liquid-cooled pipes 5 arranged axially along the shell 2. Both ends are fixed by end plates, which seal both ends of the shell 2, and end caps 4 are installed on the outside to complete the seal. This design allows the fluid to flow axially around the liquid-cooled pipes 5, improving the linear stability of the heat exchange path and reducing fluid flow losses.

[0052] Multiple inclined baffles 7 are arranged in the flow channel inside the shell 2. By controlling the fluid flow direction and creating disturbances, the laminar flow state is broken, and the thermal convection intensity between the fluid and the surface of the liquid cooling pipe 5 is enhanced. The baffles 7 are staggered, grouped, and connected with the fixing rods 6 to generate periodic disturbances and zoned flow of the fluid, thereby further improving the uniformity of heat exchange and overall efficiency.

[0053] By setting end caps 4, end plates, and through fixing rods 6, the heat exchange unit can still maintain excellent sealing performance and structural integrity under high pressure and high temperature working environment, preventing liquid leakage and loosening of internal components, and ensuring long-term stable operation of the heat exchanger.

[0054] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A heat exchanger for a triple-effect evaporator, characterized in that, It includes multiple heat exchange units connected in series. Each heat exchange unit includes a hollow shell with a flow channel inside. Multiple liquid cooling pipes are installed inside the flow channel. The shell has an inlet for receiving heat exchange liquid and an outlet for discharging heat exchange liquid outside. The inlets and outlets of adjacent heat exchange units are connected.

2. A heat exchanger for a triple-effect evaporator according to claim 1, characterized in that, The housing is a straight tube with end plates at both ends, and the liquid cooling tube is fixed to the end plates at both ends.

3. A heat exchanger for a triple-effect evaporator according to claim 1 or 2, characterized in that, The liquid cooling pipe is arranged along the axial direction of the shell.

4. A heat exchanger for a triple-effect evaporator according to claim 2, characterized in that, The housing is located inside the end plates, and both end plates have sealing heads on their outer sides.

5. A heat exchanger for a triple-effect evaporator according to claim 1, characterized in that, The shell has multiple baffles in its flow channel, and the baffles are at a predetermined angle greater than zero with respect to the axis.

6. A heat exchanger for a triple-effect evaporator according to claim 5, characterized in that, The baffles are located near the inner wall of the flow channel, and multiple baffles are arranged alternately.

7. A heat exchanger for a triple-effect evaporator according to claim 6, characterized in that, The multiple baffles are divided into multiple groups, with each group of baffles spaced apart along a straight line parallel to the axis, and the baffles from different groups are staggered.

8. A heat exchanger for a triple-effect evaporator according to claim 7, characterized in that, A fixing rod is installed between each set of baffles, and the fixing rod is set inside the flow channel.

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