CN105444594B - Plate type heat exchanger - Google Patents

Abstract

A plate-and-fin heat exchanger, including: several plates, a liquid outlet header, a liquid outlet branch pipe, an inlet branch pipe and an inlet header, wherein: each plate is provided with a concave-convex groove structure, and two plates are welded into a A group of working units forms a nodular flow channel, and the two ends of the nodular flow channel are provided with a liquid outlet branch pipe and an inlet branch pipe. The liquid outlet branch pipe is connected with the liquid outlet header, and the inlet branch pipe is connected with the inlet header. The change of the wave node shape of the exchange surface in the present invention causes the channel between the adjacent plates to be scaled, and the flow section of the external fluid between the plates increases and decreases alternately, thereby improving the heat exchange effect.

Description

Plate heat exchanger

technical field

The invention relates to the technical field of heat exchangers, in particular to a plate-fin heat exchanger.

Background technique

The traditional serpentine coil heat exchanger has poor heat exchange effect, and the processing of the serpentine coil is complicated, and the thickness of the tube wall is not conducive to heat exchange. The fouling of the serpentine coil group affects the heat transfer effect and cannot be cleaned mechanically. If it is cleaned with chemical agents, it is easy to cause corrosion and damage the equipment. The damaged pipe in the middle of the serpentine coil cannot be repaired, and the damaged pipe can only be blocked at both ends. This reduces the heat transfer area, and the heat transfer will be reduced.

Contents of the invention

The purpose of the present invention is to provide a plate-plate heat exchanger to eliminate the disadvantages of the traditional serpentine coil.

In order to solve the above technical problems, the present invention includes: several plates, liquid outlet headers, liquid outlet branch pipes, inlet branch pipes and inlet headers, wherein: each plate is provided with a concave-convex groove structure, and two plates are welded into one The group working unit forms a nodular flow channel, and the two ends of the nodular flow channel are provided with a liquid outlet branch pipe and an inlet branch pipe, the liquid outlet branch pipe is connected with the liquid outlet header, and the inlet branch pipe is connected with the inlet header.

The nodular flow channel is two cross-arranged flow channels.

The cross-sectional shape of the nodular flow channel is an ellipse with a major axis of 32 mm and a minor axis of 22 mm, and an indentation depth of 5 mm.

The various working units are supported by equidistant arrangement of spacer plates.

The middle part of each working unit is provided with a reinforcing plate, the outlet header and the inlet header are provided with fixed pipes, and the four corners of each working unit are provided with wrapping angles.

The beneficial effects of the present invention are:

The change of the shape of the wave nodes on the heat exchange surface of the plate-plate heat exchanger causes the channels between adjacent plates to be scaled, and the flow cross-section of the external fluid between the plates increases and decreases alternately, thereby improving the heat transfer effect.

The plate-plate heat exchanger adopts a double-channel corrugated form, and the velocity and direction of the medium flow are constantly changing, which disturbs the medium flow, generates turbulent flow and destroys the flow layer interface, reduces the thickness of the laminar layer; reduces the central area and the edge The temperature gradient of the zone increases the heat transfer temperature difference and obtains a larger heat release coefficient. And there is no dead angle at the corner of the runner. The surface of the plate can be fully utilized to increase the effective heat exchange area of the plate.

The metal surface area of the plate-plate heat exchanger is large, and the surface area of the water film is also large; the temperature difference between the metal plate surface and the water film is large; the spray water flows downward along the plate surface without forming a recirculation zone, the thickness of the water film is small, and the temperature As the temperature rises, the temperature difference between the cooling air and the cooling air increases, the kinetic energy of water molecules increases, and the evaporation speed increases by overcoming the surface tension of the water film. The flow channel is short and the flow resistance of the cooling air is small, which is beneficial to take away the saturated water vapor evaporated on the surface of the water film as soon as possible. The heat transfer rate of the spray water to the cooling air is greatly improved.

The plates are seam welded, and this welding flow channel makes the thickness of the plates thinner and has a higher compressive capacity. Add ribs on the side to eliminate the stress of the plate to reduce the deformation of the plate.

The plate-type heat exchange device of the present invention, in the process of assembling different numbers of plates, needs wrapping corners to fix, punching holes on the wrapping corners, so that the spray water can quickly flow back to the water tray, and can also play the role of air flow channel , so that the edge of the plate can also be cooled by fresh air.

The plate-plate heat exchanger of the present invention is composed of multiple plates. For the same amount of condensation or cooling, the plates use less material and weigh less. That is, the cold-to-weight ratio of the plate-plate heat exchanger, that is, the condensation or cooling capacity/equipment weight is greater, which is 55% larger than the cold-to-weight ratio of the serpentine coil.

Under the condition of the same size, the condensing or cooling capacity of the plate is 26.3% larger than that of the serpentine coil.

Description of drawings

Figure 1 is a schematic diagram of the structure of a plate heat exchanger.

Fig. 2 is an A-A sectional view of the plate heat exchanger.

Fig. 3 is a schematic diagram of the air flow channel of the plate.

Fig. 4 is a schematic diagram of the air flow path of the coil.

Fig. 5 is a schematic diagram of the plate flow channel.

Fig. 6 is a schematic diagram of the condensing channel of the coil.

Fig. 7 is a schematic diagram of the condensing channel of the plate.

Fig. 8 is a schematic diagram of a coiled water film.

Figure 9 is a schematic diagram of a plate-type water film.

Fig. 10 is a schematic view of the flow channel of the plate.

Figure 11 is a schematic diagram of the weld seam of the plate.

Detailed ways

The present invention will be described in further detail below in conjunction with the accompanying drawings.

As shown in Figures 1 and 2, this embodiment includes: several plates 6, liquid outlet headers 2, liquid outlet branch pipes 3, inlet branch pipes 7 and inlet headers 8, wherein: each plate 6 is provided with concave and convex Groove structure, two plates 6 are welded into a group of working units to form a nodular flow channel, the two ends of the nodular flow channel are provided with a liquid outlet branch pipe 3 and an inlet branch pipe 7, and the liquid outlet branch pipe 3 and the liquid outlet branch pipe The pipes 2 are connected, and the inlet branch pipe 7 is connected with the inlet header 8 .

The nodular channels are two intersecting channels, and the two ends of each nodal channel are respectively connected with a liquid outlet branch pipe 3 and an inlet branch pipe 7 .

The cross-sectional shape of the nodular flow channel is an ellipse with a major axis of 32 mm and a minor axis of 22 mm, and an indentation depth of 5 mm.

The various working units are supported 1 by equidistant arrangement of spacer plates. Support 1 is made of stainless steel plate with a thickness of 3mm;

A reinforcement plate 5 is provided in the middle of each working unit, a fixed pipe 9 is provided on the liquid outlet header 2 and an inlet header 8, and wrapping angles 4 are provided on the four corners of each working unit.

The outlet header 2 is formed by connecting two stainless steel pipes with a diameter of 76 mm and one stainless steel pipe with a diameter of 89 mm through a tee. The stainless steel tube with a diameter of 76mm has a thickness of 3mm, and the stainless steel tube with a diameter of 89mm has a thickness of 3.5mm;

The outlet branch pipe 3 is made of a stainless steel pipe with a diameter of 17mm, a thickness of 1.2mm, and a bending radius of 40mm;

Corner wrapping 4 is made of stainless steel plate. The corner wrapping length is 1630mm. Two rows of 29 holes with a diameter of 25mm are punched in the middle. And open 30 grooves of 14*2.8mm on the upper part, and 30 grooves of 11*2.8mm on the lower part. Corner thickness is 3mm;

The reinforcing plate 5 is made of a stainless steel plate, the length of the reinforcing plate is 1630 mm, and a row of 29 holes with a diameter of 25 mm is punched in the middle. The reinforcement plate is 72mm wide and is hemmed at the upper 15mm and lower 15mm. And open 30 grooves of 11*2.8mm in the upper and lower parts respectively. The thickness of the reinforced plate is 3mm;

Plate 6 is made of 1mm stainless steel tube plate, two steel plates are stamped and formed, then seam welded, and strengthened by reinforcing ribs on both sides;

The inlet branch pipe 7 is made of a stainless steel pipe with a diameter of 17mm and a thickness of 1.2mm. The bending radius is 40mm;

The liquid inlet header 8 is made of a stainless steel tube with a diameter of 89 mm and a thickness of 3.5 mm;

The fixed pipe 9 is made of a stainless steel pipe with a diameter of 25mm, a length of 1015mm, and a thickness of 2mm.

The specific processing flow of the sheet 6 is as follows: firstly, the thin plate is stamped into the sheet 6 so that the sheet 6 forms specific concave-convex grooves. Then the two plates 6 are welded together so that a flow channel is formed between the plates 6 . Then the plate 6 is welded on the inlet branch pipe 7 and the liquid outlet branch pipe 3 . Finally, multiple sets of plates 6 are combined through the support 1, wrap angle 4, reinforcing plate 5 and fixed pipe 9, and the branch pipes of multiple sets of plates 6 are welded on the inlet header 8 of the outlet header 2. That is, the entire production is completed.

The heat exchange process of the plates 6 is as follows: the medium to be condensed or cooled enters from the inlet header 8, and is distributed to each plate 6 through the inlet branch pipe 7, and the cooling water is evenly distributed on the outside of the plates 6. The cooling air generated by the fan flows through the channels between the plates 6, which enhances heat exchange. The condensed or cooled medium is collected by the liquid outlet branch pipe 3 into the liquid outlet header 2 and then flows out of the plate 6 heat exchange equipment. That is to complete the entire heat exchange process. The plate 6 adopts the same-course connection method, that is, the distance traveled by the medium from the inlet header 8 to the outlet header 2 is the same.

As shown in Figure 3: when the cooling air flow generated by the fan passes through the zoom-type flow channels of the adjacent plates 6, since the flow section between the plates 6 increases and decreases alternately, the air flow velocity will also decelerate and accelerate. Under the action of the wake vortex, the cooling air is affected by the tail vortex of the first channel when passing through the second channel, and the third channel is affected by the tail vortex of the second channel. Repeating this, the cooling air turbulence is stronger, and the strong The function brings better heat exchange effect between the 6 plates.

As shown in Figure 4: Compared with the plate 6 of the same height and the coil, the flow of the air flow channel of the coil is much longer than the flow channel of the plate 6, and the flow channel is narrow, the wind resistance is large, and the required fan power is less. bigger. Compared with the plate 6 evaporative condenser and the coil evaporative condenser under the same heat dissipation conditions, the fan consumption of the plate 6 type is smaller than that of the coil type, and the operation is more energy-saving.

As shown in Figure 5: the heat exchange surface of the plate-plate heat exchanger is node-shaped, and the velocity and direction of the medium flow are constantly changing, which disturbs the medium flow, and the flow can also produce turbulent flow under the condition of low Reynolds number, and obtain Larger heat release coefficient; secondly, from the perspective of the section, the medium flow channel is nodal shape, the radius of curvature is large, and the distance between the center layer and the edge is close. When the medium encounters the disturbance generated by the wave node, the center layer and the edge layer The fluid is mixed instantaneously to make the temperature of the medium uniform, reduce the temperature gradient between the central area and the edge area, increase the heat transfer temperature difference, and the heat transfer speed is faster and the effect is better.

As shown in Figure 6: Since the superheated gas will condense into a saturated liquid in the longer flow path, and this formed liquid column will cause a pressure drop, and the refrigerant liquid will be forced into the coil with the largest pressure drop or the lowest outlet pressure , As a result, the liquid column occupies the effective condensation space, which reduces the cooling effect of the system, and the exhaust pressure will increase significantly, resulting in a decrease in the heat dissipation.

As shown in Figure 7: the plates 6 enter the plate condenser from both ends above, and pass through double cross flow channels to make the arrangement more compact, reduce the heat transfer resistance, and improve the heat exchange efficiency. Condensation is shorter, liquid drains faster and pressure drop is smaller.

As shown in Figure 8: when the coil condenser operates in the same direction as wind and water, a "dry spot area" will be formed at the bottom of the tube to reduce the effective heat exchange area of the coil, and fouling will easily occur around the "dry spot area". Reduce the heat transfer coefficient of the coil and reduce the heat transfer.

As shown in Figure 9: the spray water is directly sprayed onto the surface of the wave nodes of the plates 6, the contact area is large, the water film is thin and uniform, and the evaporation effect is good. The continuity of the water film is good, and the flow rate is faster, and the heat transfer effect is better.

As shown in Figure 10: the plate 6 adopts the double-channel condensation form, and there is no dead angle at the corner of the flow channel. The surface of the plate 6 is fully utilized to increase the effective heat exchange area of the plate 6 .

As shown in FIG. 11 , the plate 6 is in the form of seam welding, and this welding flow path makes the thickness of the plate 6 thinner, and the state of compression is higher, which can save materials. And the contact between the weld seam and the runner can also play a role in enhancing heat transfer.

Claims (3)

1. a kind of plate type heat exchanger, which is characterized in that including：Several plates go out liquid collector, go out liquid branched pipe, import branch Pipe and inlet header, wherein：Each plate is equipped with concave convex groove structure, and plate is welded as one group of working cell and forms node shape two-by-two Liquid branched pipe and import branched pipe is provided in the both ends of runner, node shape runner, goes out liquid branched pipe and is connected with liquid collector is gone out, import Branched pipe is connected with inlet header；

The node shape runner is two runners arranged in a crossed manner；

The cross sectional shape of the node shape runner is ellipse, long axis 32mm, the ellipse of short axle 22mm, depth of cup 5mm；

Cornerite is set on four angles of each working cell, and cornerite is equipped with punching.

2. plate type heat exchanger according to claim 1, which is characterized in that each working cell is by distance plate etc. Away from arrangement support.

3. plate type heat exchanger according to claim 2, which is characterized in that the middle part of each working cell is arranged Reinforcing plate goes out on liquid collector and inlet header and fixing pipe is arranged.