Magnetic assisted plate-fin heat exchanger baffle head structure and adaptive adjustment method

Abstract

The present invention discloses a magnetic-assisted plate-fin heat exchanger baffle head structure and an adaptive adjustment method. It includes a head shell, a head inlet pipe, a baffle and an electromagnet; the head inlet pipe is arranged at the upper end of the head shell and communicates with the inlet end of the head shell; the bottom of the head shell serves as the head outlet surface, and multiple rows of outlet channels are evenly spaced on the head outlet surface; multiple baffles with variable inclination angles are evenly installed between the front and rear side surfaces of the head shell through baffle shaft seals; three electromagnets are installed on the left and right sides of the head shell. The present invention obtains an adaptive baffle inclination angle at different head inlet flow rates through the action of magnetic force, so that the head can obtain a uniform outlet flow rate at different inlet flow rates.

Description

Technical Field

[0001] The present invention belongs to the technical field of plate-fin heat exchanger head structures and relates to an internal structure of a heat exchanger and an adjustment method, and in particular to a magnetic-assisted plate-fin heat exchanger baffle head structure and an adaptive adjustment method. Background Art

[0002] Plate-fin heat exchangers are widely used in aerospace, petroleum metallurgy, air separation equipment and other industries due to their compact structure and high heat transfer efficiency. They are often used as core components of large equipment. After the fluid involved in heat exchange enters the heat exchanger, the first thing it enters is the heat exchanger head. Uneven inlet flow distribution is an important part of the optimization design of the heat exchanger inlet section, and structural innovation of the head is an important means to improve the uneven distribution of fluid inlet flow. A good head structure can distribute the fluid entering the heat exchanger as evenly as possible to ensure high efficiency of heat transfer.

[0003] Chinese invention patent 201910037082.X discloses a plate-fin heat exchanger baffle nozzle structure head, which adds a baffle at the end of the head main pipe so that the inflowing high-pressure gas can be sprayed to the corresponding outlet area, effectively improving the uniformity of flow distribution at each outlet. This structure improves the uniformity of flow distribution of the fluid at the outlet and has low energy loss, but it does not take into account the complexity of the working conditions of the heat exchanger in actual operation. This fixed structure cannot achieve uniform distribution of outlet flow at different fluid flow rates.

[0004] By improving the baffle head structure and providing control assistance, uniform inlet flow distribution under different inlet flow rates can be achieved, which is in line with the actual working conditions of the constantly changing inlet flow rate during the operation of the heat exchanger. Summary of the invention

[0005] In order to solve the problems in the background technology, the present invention provides a magnetic-assisted plate-fin heat exchanger baffle head structure and an adaptive adjustment method to improve the distribution of gas entering the heat exchanger under different working conditions.

[0006] The technical solution of the present invention is as follows:

[0007] 1. A magnetically assisted plate-fin heat exchanger baffle head structure

[0008] The present invention comprises a head shell, a head inlet pipe, a baffle and an electromagnet; the head inlet pipe is arranged at the upper end of the head shell and communicates with the inlet end of the head shell; the bottom of the head shell serves as the head outlet surface, and the head outlet surface is evenly spaced with multiple columns of outlet channels for fluid outflow; multiple baffles with variable inclination angles are evenly installed between the side surfaces on both sides perpendicular to the direction of the outlet channel inside the head shell through baffle shaft seals, and the baffles are parallel to the outlet channel; three electromagnets with different heights are installed on the side surfaces on both sides of the head shell perpendicular to the direction of the outlet channel.

[0009] Baffle shaft seals are fixed on the front and rear sides of the head shell. The baffle shaft seals are located at the fluid inlet end of the head shell. The baffle shaft seals are evenly spaced with mounting holes with the same number as the baffles. The baffle shafts arranged on both sides of the upper end of each baffle extend into the mounting holes of the baffle shaft seals on the front and rear sides respectively. The baffle shafts cooperate with the corresponding mounting holes to form an articulated kinematic pair. The baffle can adjust the baffle arrangement inclination angle by rotating around its own baffle shaft.

[0010] The three electromagnets are electromagnet I, electromagnet II and electromagnet III. Electromagnet I, electromagnet II and electromagnet III are arranged on the same side of the head shell from top to bottom and are located on the outer side.

[0011] The baffle plate in the middle is a non-magnetic baffle plate, and the other baffle plates are magnetic baffle plates; the magnetic baffle plates are evenly distributed on both sides of the non-magnetic baffle plate, the two outermost magnetic baffle plates on both sides are outer magnetic baffle plates, the two magnetic baffle plates close to the non-magnetic baffle plates are inner magnetic baffle plates, and the other magnetic baffle plates are middle magnetic baffle plates;

[0012] The magnetic material placement height of the outer magnetic baffle corresponds to electromagnet II, the magnetic material placement height of the middle magnetic baffle corresponds to electromagnet I, and the magnetic material placement height of the inner magnetic baffle corresponds to electromagnet III. The magnetic pole direction of the magnetic material in the magnetic baffle is different from the direction of the corresponding electromagnet.

[0013] The number of outlet channels corresponds to the same number of baffles.

[0014] The middle sections of the left and right sides of the head shell are arc-shaped and bend outwards. The starting end of the arc is 1.5 meters away from the inlet end of the head. The arc center angle is 25°~35°, and the radius is 0.9L~1.1L, where L is the length of the head outlet surface.

[0015] The arc-shaped shell is suitable for the flow form of the fluid inside the head, which can reduce the generation of vortices on both sides of the head inlet, and the outlet channels at both ends of the head outlet surface can be allocated a reasonable fluid flow.

[0016] A flow meter is provided on one side of the head inlet pipe, and the flow meter is used to detect the flow velocity V of the fluid inlet.

[0017] 2. Adaptive adjustment method of the baffle head structure of the magnetically assisted plate-fin heat exchanger

[0018] The following steps are involved:

[0019] Step 1) energize the electromagnets on the left and right sides of the head shell, so that the electromagnets generate attraction to the magnetic baffles corresponding to themselves, causing the baffles to tilt;

[0020] The flow meter detects the inlet flow velocity V of the fluid, and the flow detection device detects the flow velocities v1~v1 of each outlet channel respectively. n , calculate the dimensionless outlet velocity non-uniformity of all outlet channels Calculate the relative non-uniformity of the outlet flow rate of each outlet channel

[0021] Where n is the total number of outlet channels; i represents the i-th outlet channel, where i∈(1,2,3...n); v i is the flow rate of the ith outlet channel, is the average flow velocity of all outlet channels;

[0022] Step 2) Increase the current I1 of the electromagnet II and make a judgment: if the relative unevenness s of the outer magnetic baffle corresponding to the outlet channel i decreases, then continue to increase the current I1 of the electromagnet II; if the relative unevenness s of the outer magnetic baffle corresponding to the outlet channel i increases, the current I1 of the electromagnet II is reduced; until the relative unevenness s i The fluctuation is less than the first set value Δs i ;

[0023] Step 3) Increase the current I2 of electromagnet I and the current I3 of electromagnet III in sequence, and calculate the relative unevenness s of the outlet channel corresponding to the middle magnetic baffle and the inner magnetic baffle i , use the method of step 2) to adjust the current I2 of electromagnet Ⅰ and the current I3 of electromagnet Ⅲ respectively. The current I2 of electromagnet Ⅰ corresponds to

[0024] The relative unevenness of the outlet channel corresponding to the intermediate magnetic baffle is the relative unevenness s of each outlet channel corresponding to all the intermediate magnetic baffles. i Add.

[0025] Step 4) Calculate the outlet flow velocity unevenness s after the current changes * , and make a judgment: If the outlet flow velocity unevenness s * decreases, the currents I1, I2 and I3 increase simultaneously; if the outlet flow velocity unevenness s * increases, the currents I1, I2 and I3 are reduced simultaneously until s* The fluctuation amount is less than the second set value Δs * ;

[0026] Step 5) Real-time detection of the inlet flow rate V and the flow rates v1~v1 of each outlet channel n , and calculate the outlet velocity unevenness s * , the outlet velocity non-uniformity s * The fluctuation exceeds the second set value Δs * Repeat steps 2 to 4 at the same time, and change the inclination angle of the magnetic baffle by changing the current of the electromagnet, so that the flow of each outlet channel is kept evenly distributed under the changing inlet flow rate V.

[0027] The increase or decrease value of the current of the electromagnet in each adjustment in step 2) and step 3) is a preset minimum current change ΔI;

[0028] The increase or decrease values ​​of each adjustment of the currents I1, I2 and I3 in step 4) are respectively

[0029] The n exit channels from left to right correspond to the n baffles from left to right, and the middle exit channel corresponds to the non-magnetic baffle.

[0030] Beneficial effects of the present invention:

[0031] 1) The present invention obtains an adaptive baffle inclination angle at different head inlet flow rates through the action of magnetic force, so that the head can obtain a uniform outlet flow rate at different inlet flow rates.

[0032] 2) The present invention adopts a composite material baffle with magnetic properties and a magnetic generating device to adjust the baffle inclination angle. Compared with adjusting the baffle inclination angle by a mechanical structure, the integrity of the head structure is protected and the processing and manufacturing is easier.

[0033] 3) The present invention adopts an arc-shaped shell, which conforms to the flow form of the fluid inside the head, can avoid the generation of eddy currents on both sides of the head inlet, and the outlets at both ends of the head can be allocated a reasonable fluid flow. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a schematic diagram of the two-dimensional structure of the present invention;

[0035] Figure 2 It is a schematic diagram of the three-dimensional structure of the present invention;

[0036] Figure 3 This is a structural diagram of the head shell of the present invention;

[0037] Figure 4 It is a schematic diagram of the overall three-dimensional structure of the present invention;

[0038] Figure 5 To control the working process of the present invention;

[0039] In the figure: 1-head inlet pipe, 2-baffle, 3-electromagnet I, 4-electromagnet II, 5-electromagnet III, 6-exit channel, 7-head outlet surface, 11-baffle shaft seal, 12-flow meter, 13-baffle shaft. DETAILED DESCRIPTION

[0040] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0041] like Figure 1 and Figure 2 As shown, the present invention includes a head shell, a head inlet pipe 1, a baffle 2 and an electromagnet. The overall structure of the head of the present invention is welded, including the connection between the head inlet pipe 1 and the lower end head shell, the connection between the side cover plate of the head shell and the whole, and the left and right sides of the head shell adopt an arc structure. Multiple columns of outlet channels 6 for fluid outflow are evenly spaced on the head outlet surface 7 at the bottom of the head shell. Electromagnets I3, II4 and III5 are arranged on the left and right outer sides of the head shell from top to bottom.

[0042] like Figure 1 and Figure 4 As shown, baffle shafts are arranged on both sides of the upper end of the baffle 2, and baffle shaft seals 11 are fixed to the front and rear sides of the head shell. Each baffle 2 is connected to the baffle shaft seal 11 through a baffle shaft 13 to form a sliding shaft kinematic pair, and the baffle shaft 13 is located at the fluid inlet end of the head shell. The magnetic baffle can rotate around its baffle shaft to make the baffle inclination angle different.

[0043] The baffles are made of magnetic and non-magnetic materials. The central vertical baffle is non-magnetic material, and the other baffles are baffles with magnetic materials installed at specific heights. The baffles close to the center side are placed with magnetic materials at the same height as the corresponding electromagnet Ⅲ5, the baffles close to the two sides are placed with magnetic materials at the same height as the corresponding electromagnet II4, and the baffles in the middle are placed with magnetic materials at the same height as the corresponding electromagnet Ⅰ3. The magnetic poles have different directions relative to the nearby electromagnets. The smaller the distance from the center baffle, the smaller the magnetism, and the larger the distance from the center baffle, the greater the magnetism. The number of baffles is equal to the number of head outlets, and there are n outlets or baffles in total.

[0044] like Figure 3 As shown in the figure, the middle sections of the left and right sides of the head shell are arc-shaped and bend outward, and the starting end of the arc is 1.5 meters away from the inlet end of the head. The arc center angle is 25°~35°, and the radius is 0.9L~1.1L, where L is the length of the head outlet surface 7. The arc between the end of the middle arc and the head outlet surface 7 is an arc that bends inward. The arc shell is suitable for the flow form of the fluid inside the head, which can reduce the generation of vortices on both sides of the head inlet, and the outlet channels at both ends of the head outlet surface can be allocated to a reasonable fluid flow. Specific embodiment:

[0046] like Figure 5 As shown, the magnetic field is adjusted according to the flow rate V of the inlet pipe of the head and the unevenness of the outlet flow, so as to realize the adaptive adjustment of the inclination angle of each magnetic baffle and improve the uniformity of the fluid distribution of the head, including the following steps:

[0047] Step 1) Power on the electromagnets on the left and right sides of the head shell, so that the electromagnets generate attraction to the corresponding magnetic baffles, causing the baffles to tilt; the inlet flow rate V of the fluid is detected by the flow meter 12, and the flow rates v1~v1 of each outlet channel 6 are detected by the flow detection device. n , calculate the dimensionless outlet velocity non-uniformity Calculate the relative unevenness of each outlet

[0048] Step 2) Increase the current I1 of the electromagnet II4 by a minimum current change ΔI, and make a judgment: if the relative unevenness s of the outlet channel corresponding to the outer magnetic baffle is i decreases, then continue to increase the current I1 of the electromagnet II4 by a ΔI; if the relative unevenness s of the outer magnetic baffle corresponding to the outlet channel i increases, the current I1 of the electromagnet II4 is reduced by a ΔI; until the relative unevenness s i The fluctuation is less than the first set value Δs i ;

[0049] Step 3) Increase the current I2 of the electromagnet Ⅰ3 by a minimum current change ΔI, and change the relative unevenness s of each outlet channel corresponding to all intermediate magnetic baffles i The relative unevenness of the outlet channel corresponding to the intermediate magnetic baffle is obtained by adding them together, and a judgment is made: if the relative unevenness of the outlet channel corresponding to the intermediate magnetic baffle decreases, the current I2 of the electromagnet Ⅰ3 continues to increase by one ΔI; if the relative unevenness of the outlet channel corresponding to the intermediate magnetic baffle increases, the current I2 of the electromagnet Ⅰ3 is reduced by one ΔI; until the fluctuation amount of the relative unevenness of the outlet channel corresponding to the intermediate magnetic baffle is less than the first set value Δs i ;

[0050] Increase the current I3 of the electromagnet III5 by a minimum current change ΔI, and make a judgment: if the relative unevenness s of the outlet channel corresponding to the inner magnetic baffle is i If the relative unevenness s of the inner magnetic baffle corresponding to the outlet channel is i increases, the current I3 of the electromagnet III5 is reduced by a ΔI; until the relative unevenness s i The fluctuation is less than the first set value Δs i ;

[0051] Step 4) Calculate the outlet flow velocity unevenness s after the current changes * , and make a judgment: If the outlet flow velocity unevenness s * decreases, the current I1 increases at the same time Current I2 increases Current I3 increases If the outlet flow rate is uneven, s * increases, the current I1 decreases at the same time Current I2 decreases Current I3 decreases Until s * The fluctuation amount is less than the second set value Δs * ;

[0052] Step 5) Real-time detection of the inlet flow velocity V and the flow velocities v1 to v2 of each outlet channel 6 n , and calculate the outlet velocity unevenness s * , the outlet velocity non-uniformity s * The fluctuation exceeds the second set value Δs * Repeat steps 2 to 4. By adaptively changing the current of the electromagnet group, the inclination angle of the magnetic baffle inside the head is adaptively changed, so that the flow velocity non-uniformity of the head outlet channel converges, so that the head can have better outlet flow distribution characteristics under the changing inlet flow velocity V.

Claims

1. A magnetically assisted plate-fin heat exchanger baffle head structure, characterized in that: The invention comprises a head shell, a head inlet pipe (1), a baffle (2) and an electromagnet; the head inlet pipe (1) is arranged at the upper end of the head shell and communicates with the inlet end of the head shell; the bottom of the head shell serves as a head outlet surface (7), and a plurality of rows of outlet channels (6) are evenly spaced on the head outlet surface (7); a plurality of baffles (2) with variable inclination angles are evenly spaced between the side surfaces on both sides perpendicular to the direction of the outlet channels inside the head shell through baffle shaft seals (11), and the baffles (2) are parallel to the outlet channels (6); three electromagnets of different heights are installed on the side surfaces on both sides of the head shell perpendicular to the direction of the outlet channels; The front and rear sides of the head shell are both fixed with baffle shaft seals (11), the baffle shaft seals (11) are located at the fluid inlet end of the head shell, and the baffle shaft seals (11) are evenly spaced with mounting holes having the same number as the baffles; baffle shafts (13) arranged on both sides of the upper end of each baffle (2) extend into the mounting holes of the baffle shaft seals (11) on the front and rear sides respectively, and the baffle shafts (13) cooperate with the corresponding mounting holes to form an articulated kinematic pair, and the baffle can adjust and change the arrangement inclination angle of the baffle (2) by rotating around its own baffle shaft (13); The number of outlet channels (6) corresponds to the same number of baffles (2); A flow meter (12) is provided on one side of the end cap inlet pipe (1), and the flow meter (12) is used to detect the flow velocity V of the fluid inlet.

2. A magnetically assisted plate-fin heat exchanger baffle head structure according to claim 1, characterized in that: The three electromagnets are electromagnet I (3), electromagnet II (4) and electromagnet III (5), which are arranged on the same side of the head shell from top to bottom.

3. A magnetically assisted plate-fin heat exchanger baffle head structure according to claim 2, characterized in that: The baffle plate (2) located in the middle is a non-magnetic baffle plate, and the other baffle plates (2) are all magnetic baffle plates; the magnetic baffle plates are evenly distributed on both sides of the non-magnetic baffle plate, the two outermost magnetic baffle plates on both sides are outer magnetic baffle plates, the two magnetic baffle plates close to the non-magnetic baffle plates are inner magnetic baffle plates, and the other magnetic baffle plates are middle magnetic baffle plates; The magnetic material placement height of the outer magnetic baffle corresponds to the electromagnet II (4), the magnetic material placement height of the middle magnetic baffle corresponds to the electromagnet I (3), and the magnetic material placement height of the inner magnetic baffle corresponds to the electromagnet III (5).

4. The magnetically assisted plate-fin heat exchanger baffle head structure according to claim 1, characterized in that: The middle sections of the left and right sides of the head shell are arc-shaped and bend outwards. The starting end of the arc is 1.5 meters away from the inlet end of the head. The arc center angle is 25° to 35°, and the radius is 0.9L to 1.1L, where L is the length of the head outlet surface (7).

5. The method for adaptively adjusting the baffle head structure of a magnetically assisted plate-fin heat exchanger according to any one of claims 1 to 4 comprises the following steps: Step 1) energizing the electromagnets on the left and right sides of the head shell, so that the electromagnets generate attraction for the magnetic baffles (2) corresponding to themselves, causing the baffles to tilt; The inlet flow rate V of the fluid is detected by a flow meter (12), and the flow rates v1 to v2 of each outlet channel (6) are detected respectively by a flow detection device. n , calculate the dimensionless outlet velocity non-uniformity of all outlet channels Calculate the relative non-uniformity of the outlet flow rate of each outlet channel Where n is the total number of outlet channels; i represents the i-th outlet channel, where i∈(1,2,3...n); v i is the flow rate of the ith outlet channel, is the average flow velocity of all outlet channels; Step 2) Increase the current I1 of the electromagnet II (4) and make a judgment: if the relative unevenness s of the outlet channel corresponding to the outer magnetic baffle is i decreases, then continue to increase the current I1 of the electromagnet II (4); if the relative unevenness s of the outer magnetic baffle corresponding to the outlet channel i increases, the current I1 of the electromagnet II (4) is reduced until the relative unevenness s i The fluctuation is less than the first set value △s i ; Step 3) The current I2 of the electromagnet Ⅰ (3) and the current I3 of the electromagnet Ⅲ (5) are increased in sequence, and the relative unevenness of the outlet channels corresponding to the middle magnetic baffle and the inner magnetic baffle is calculated. The current I2 of the electromagnet Ⅰ (3) and the current I3 of the electromagnet Ⅲ (5) are adjusted respectively by the method of step 2). The current I2 of the electromagnet Ⅰ (3) corresponds to Step 4) Calculate the outlet flow velocity unevenness s after the current changes * , and make a judgment: If the outlet flow velocity unevenness s * decreases, the currents I1, I2 and I3 increase simultaneously; if the outlet flow velocity unevenness s * increases, the currents I1, I2 and I3 are reduced simultaneously until s * The fluctuation is less than the second set value △s * ; Step 5) Real-time detection of the inlet flow rate V and the flow rates v1 to v2 of each outlet channel (6) n , and calculate the outlet velocity unevenness s * , the outlet velocity non-uniformity s * The fluctuation exceeds the second set value △s * Repeat steps 2 to 4 at the same time, and change the inclination angle of the magnetic baffle by changing the current of the electromagnet, so that the flow of each outlet channel is kept evenly distributed under the changing inlet flow rate V.

6. The method for adaptively adjusting the baffle head structure of a magnetically assisted plate-fin heat exchanger according to claim 5, characterized in that: The increase or decrease value of the current of the electromagnet in each adjustment in step 2) and step 3) is a preset minimum current change ΔI; The increase or decrease values ​​of each adjustment of the currents I1, I2 and I3 in step 4) are respectively 7. The method for adaptively adjusting the baffle head structure of a magnetically assisted plate-fin heat exchanger according to claim 5, characterized in that: The n outlet channels (6) from left to right correspond to the n baffles from left to right respectively, and the middle outlet channel (6) corresponds to the non-magnetic baffle.

Images