A shell and tube condenser with variable flow channel for efficiency

Abstract

The utility model discloses a variable runner efficiency improving shell and tube condenser relates to heat exchange equipment field, aims at solving traditional condenser air distribution uneven, condensate accumulation, heat exchange efficiency low etc. It includes the cylinder, is equipped with the air inlet pipe, the liquid outlet pipe on the cylinder, is equipped with the heat exchange pipe, the air equalizing plate, the deflector and a plurality of skimming plates in the cylinder through the tube plate. The deflector is obliquely arranged in the upper part of the cylinder, the connecting end is closed and is lower than the free end, and the free end leaves the air gap with the cylinder wall, the air equalizing plate is obliquely arranged above the deflector, and the deflector lower end has the air equalizing opening, and the skimming plate is obliquely arranged below the deflector, and the low end leaves the liquid drop channel, and the high end leaves the air gap. The cooling area between the deflector and the air equalizing plate is used for discharging the sensible heat of overheated gas, and the condensing area below the deflector is used for discharging the latent heat of gas to make it condense, and the supercooling section can be arranged in the cylinder to realize the supercooling of liquid. The condenser can optimize the gas-liquid flow, improve the heat exchange efficiency, and be suitable for refrigeration or heat pump system.

Description

Technical Field

[0001] This solution relates to the field of heat exchange equipment, specifically to a variable flow channel shell-and-tube condenser for improved efficiency. Background Technology

[0002] Shell-and-tube condensers, as a type of heat exchanger, are frequently used in refrigeration or heat pump systems. The gaseous refrigerant discharged from the compressor typically retains a certain degree of superheat. It enters the condenser's inlet pipe from the compressor's discharge pipe, then flows through the condenser's inlet pipe into the condenser shell. Passing through the distribution plate, the refrigerant gas is evenly distributed along the length of the condenser. The superheated refrigerant undergoes indirect heat exchange with water through the heat exchange tube walls, condensing into liquid refrigerant that drips to the bottom of the shell.

[0003] A subcooler is usually installed at the bottom of the condenser to cool the condensate to a subcooled state, thereby improving the system's circulation efficiency.

[0004] The heat exchange efficiency of the condenser directly affects the system's cycle efficiency. Improving the heat exchange efficiency of the condenser plays a key role in enhancing the unit's efficiency and reducing costs.

[0005] Traditional shell-and-tube condensers suffer from uneven gas distribution, condensate buildup leading to decreased heat exchange efficiency, and low utilization of tube space. While some improvements have been made, such as installing inclined baffles in the vertical direction to allow condensate to flow away instead of dripping onto the lower heat exchange tubes, thus mitigating the problem of low heat exchange efficiency caused by condensate buildup on the tube walls, further improvements in this area are currently stagnant, limiting the potential for increased heat exchange efficiency. Therefore, we offer a new solution to further enhance the heat exchange efficiency of condensers. Summary of the Invention

[0006] The technical problem to be solved by this utility model is to provide a variable flow channel shell-and-tube condenser with improved efficiency.

[0007] The specific technical solution of this utility model to solve the above-mentioned technical problems is as follows: A variable flow channel shell-and-tube condenser includes a shell, an inlet pipe and an outlet pipe disposed on the shell, a heat exchange tube group, a gas distribution plate, a flow guide plate and several skimming plates disposed in the shell via a tube sheet; The guide plate is inclinedly disposed in the upper part of the cylinder. The end of the guide plate connected to the cylinder is closed. The connected end is lower than the free end of the guide plate. There is a gap between the free end and the inner wall of the cylinder to allow gas to pass through. The air distribution plate is inclined above the guide plate, and the lower end of the guide plate is provided with an air distribution opening; Several skimming plates are spaced apart and inclined below the guide plate, and the lower end of each skimming plate is provided with a channel for liquid to drip; the higher end of each skimming plate is provided with a spacing for gas to pass through. The space between the guide plate and the gas equalization plate is a cooling zone, mainly used to displace and discharge the sensible heat of the superheated gas entering through the inlet pipe. The distance between the guide plate and the gas equalization plate is such that when the superheated gas entering through the inlet pipe leaves the cooling zone, its temperature only drops to near the condensation point, and not below the condensation point. This ensures that under normal operating conditions, the gas medium will not condense into a liquid in the cooling zone. Therefore, the connection end between the guide plate and the cylinder can be set as closed, forcing the gas medium to flow from the lower connection end to the higher free end. At the same time, the distance between the guide plate and the gas equalization plate can be designed according to the most commonly used operating conditions in the design to increase the flow velocity of the gas medium in the cooling zone and improve the heat exchange efficiency.

[0008] The area below the baffle plate is a condensation zone, which is mainly used to displace the latent heat of the gas cooled from the cooling zone and condense the gas into a liquid.

[0009] Furthermore, the outer side of one end of the tube sheet inside the cylinder is a water chamber section, and the outer side of the other end of the tube sheet is a baffle section. The water chamber section is also provided with a water chamber baffle plate, which is used to isolate the inlet water and the outlet water. It cooperates with the tube sheet to form an inlet water chamber and a return water chamber. One half of the heat exchange tubes is connected to the inlet water chamber, and the other half is connected to the return water chamber. The water chamber baffle plate is inclined. The heat exchange tubes connected to the inlet water chamber are closer to the channel for liquid dripping than the heat exchange tubes connected to the return water chamber. The heat exchange tubes connected to the return water chamber are closer to the spacing for gas to pass through than the heat exchange tubes connected to the inlet water chamber.

[0010] Furthermore, the gas equalization plate is parallel to the guide plate, and the skimming plate is parallel to the guide plate; Furthermore, the guide plate is provided with a drain hole at the connection end to allow the liquid that condenses in the cooling zone in advance under non-standard operating conditions to flow down and avoid it from accumulating above the guide plate. Furthermore, the minimum distance between the skimming plate and the heat exchange tube located above it is greater than 6 mm; Furthermore, the minimum distance between the guide plate and the heat exchange tube located above it is greater than 6 mm; Furthermore, it also includes a supercooled cover plate, a supercooled pipe is provided below the supercooled cover plate, a channel for liquid to pass through is provided on the supercooled cover plate, and the supercooled pipe is connected to the water inlet chamber; the space located below the supercooled cover plate is a supercooled section, which is used to cool the condensed liquid to a supercooled state, and the liquid outlet pipe is located below the supercooled pipe.

[0011] Furthermore, the heat exchange tube is inclined in the axial direction.

[0012] Furthermore, the total area of ​​the air distribution openings on the air distribution plate is greater than the cross-sectional area of ​​the air intake pipe, and the opening area closer to the air intake pipe is greater than the opening area farther away from the air intake pipe.

[0013] Furthermore, the gas equalization opening is elongated. Attached Figure Description

[0014] Figure 1 This is a perspective sectional view of the end of the variable flow channel efficiency-enhancing shell-and-tube condenser of this utility model. Figure 2 This is a schematic diagram of the air distribution plate viewed from a perspective perpendicular to the intake pipe in the embodiment. Figure 3 This is a structural diagram of the area near the intake pipe in the embodiment; Figure 4 This is a top sectional view of the subcooled section in the embodiment (the heat exchange tubes are omitted).

[0015] The following is a list of component names represented by the reference numerals in the attached diagram: 1. Inlet pipe; 2. Gas distribution plate; 201. First gas distribution plate; 202. Second gas distribution plate; 203. Third gas distribution plate; 204. Fourth gas distribution plate; 205. Fifth gas distribution plate; 3. Flow guide plate; 4. Skimming plate; 5. Subcooling cover plate; 6. Subcooling baffle support plate; 7. Liquid outlet pipe; 8. Support plate; 801. First support plate; 802. Second support plate; 803. Third support plate; 804. Fourth support plate; 9. Cylinder body; 10. Water chamber baffle plate; 11. Condenser water outlet pipe; 12. Condenser water inlet pipe; 13. Tube sheet. Detailed Implementation

[0016] The principles and features of this utility model are described below with reference to the accompanying drawings. The examples given are only for explaining this utility model and are not intended to limit the scope of this utility model.

[0017] like Figure 1 As shown, a variable flow channel shell-and-tube condenser mainly includes an inlet pipe 1, a gas distribution plate 2, a guide plate 3, a skimming plate 4, a subcooling cover plate 5, a subcooling baffle plate 6, a liquid outlet pipe 7, a support plate 8, a cylinder 9, a water chamber baffle 10, a condenser water outlet pipe 11, and a condenser water inlet pipe 12. The densely packed round holes are heat exchange tubes fixed by a tube sheet 13.

[0018] The guide plate 3 is inclinedly disposed in the upper part of the cylinder 9. The end of the guide plate 3 connected to the cylinder 9 is closed. The connected end is lower than the free end of the guide plate 3. A gap is provided between the free end and the inner wall of the cylinder 9 to allow gas to pass through. The air distribution plate 2 is inclinedly disposed above the guide plate 3, and the lower end of the guide plate 3 is provided with an air distribution opening; Several skimming plates 4 are spaced apart and inclined below the guide plate 3, and the lower end of each skimming plate 4 is provided with a channel for liquid to drip; the higher end of each skimming plate 4 is provided with a spacing for gas to pass through. like Figure 1 As shown, the air inlet pipe 1 and the air distribution plate 2 form an air distribution channel. The cross-sectional area of ​​the air distribution channel (shaded area) is set to 1.25 to 1.5 times the cross-sectional area of ​​the air inlet pipe 1. After the gas enters the air distribution channel from the air inlet pipe 1, it is blocked by the air distribution plate 2 and flows to both sides of the cylinder 9 axis. That is, the total gas flow area is 2.5 to 3 times that of the air inlet pipe 1, so it will not cause a large gas resistance loss.

[0019] The condenser is roughly divided into three heat exchange sections: cooling section, condensing section, and subcooling section.

[0020] In principle, the cooling section is only used to displace the sensible heat of the superheated gas, causing its temperature to drop while maintaining its gaseous state. Therefore, the gas generally does not condense into a liquid in this section.

[0021] The cooling section is formed by a combination of a gas distribution plate 2, a guide plate 3, and a cylindrical body. After the superheated gas enters this area through the inlet pipe 1, it exchanges heat with the cooling water in the heat exchange tubes within this area, transferring sensible heat to the cooling water to achieve cooling. Due to the carefully designed spacing between the guide plate 3 and the gas distribution plate 2, the airflow speed can be controlled, ensuring that under normal operating conditions, the temperature of the superheated gas drops to near the condensation point when leaving the cooling section, but does not fall below the condensation point. This design ensures that the gas medium does not condense into a liquid in the cooling section under normal operating conditions. The sealed connection between the guide plate 3 and the cylindrical body forces the gas medium to flow from the lower connecting end to the higher free end, fully exchanging heat with the heat exchange tubes within the area, thereby significantly improving heat exchange efficiency.

[0022] In addition, the gas equalization openings on the gas equalization plate 2 also play an important role. The gas equalization opening area near the air inlet pipe 1 is larger than that far from the air inlet pipe 1. This design allows the gas to be distributed more evenly in the axial direction of the cylinder 9, further optimizing the heat exchange effect. Moreover, the elongated gas equalization opening design also helps the gas flow smoothly.

[0023] As mentioned above, under normal circumstances, no condensate is generated in the cooling section. However, if the system operates under unconventional conditions, such as under ultra-low load conditions, the gas may still condense in the cooling zone. In order to prevent the liquid that has condensed prematurely from accumulating in large quantities above the guide plate 3, a drain hole is opened at a lower position on the right side of the guide plate 3 so that the condensed liquid can be discharged to the lower condensation zone.

[0024] The condensation zone is provided with several skimming plates 4, which divide the condensation zone into four parallel sub-regions. The higher end of the skimming plate 4 is provided with a gap for gas to pass through, and the right side (i.e. the lower end) of the skimming plate 4 is provided with a channel for liquid to drip between it and the inner wall of the cylinder 9.

[0025] The gas equalization plate 2 is parallel to the guide plate 3, and the skimming plate 4 is parallel to the guide plate 3. This makes the airflow more stable, and each sub-region of the condensation zone can have approximately the same heat exchange stroke, thus achieving a relatively consistent heat exchange effect.

[0026] Gas approaching the condensation point from the cooling zone moves in the direction shown by the arrows in the diagram, entering the four sub-regions of the condensation zone for heat exchange. The skimming plate 4 collects the liquid condensed in the upper sub-region, allowing the condensate to flow quickly through the liquid channel to the non-tube area of ​​the cylinder wall via the skimming plate 4. This reduces the amount of liquid adhering to the lower tube group, thins the liquid film on the heat exchange tubes, and improves the heat exchange efficiency of the condensation section. This structural improvement changes the gas flow direction from top to bottom in the traditional design to a lateral flow from left to right. Furthermore, the heat exchange tubes are also inclined in the axial direction (15° in this example), facilitating the accumulation of droplets along the heat exchange tubes for rapid detachment.

[0027] The subcooling section is located at the bottom of the cylinder 9 and consists of a subcooling cover plate 5 and subcooling pipes (i.e., heat exchange pipes located in the subcooling section). The condensate flowing down from the condensation zone enters the subcooling section through the channel on the subcooling cover plate 5. Cooling water is circulated in the subcooling pipes, and the condensate exchanges heat with the cooling water in the subcooling pipes to further reduce the temperature to a subcooled state.

[0028] A water chamber partition 10 is provided on the tube sheet 13 at one end of the cylinder 9. The water chamber partition 10 is used to isolate the inlet water and the outlet water. It cooperates with the tube sheet 13 and the cylinder 9 to form an inlet water chamber and a return water chamber. One half of the heat exchange tube is connected to the inlet water chamber, and the other half is connected to the return water chamber.

[0029] The water chamber baffle 10 is located at the center line of the number of pipes in the pipe section, and the water chamber baffle 10 is inclined. The heat exchange tube connected to the inlet water chamber is closer to the channel for liquid dripping than the heat exchange tube connected to the return water chamber, and the heat exchange tube connected to the return water chamber is closer to the spacing for gas passage than the heat exchange tube connected to the inlet water chamber. The condenser inlet pipe 12 is the first tube pass, and the outlet pipe is the second tube pass. The first pass has a lower water temperature and a larger heat flux density. The shell-side gas can obtain greater gas flow potential energy because more gaseous refrigerant condenses into liquid here, reducing its volume and forming a pressure difference, thereby giving the gas greater flow potential energy. Figure 4This is a top sectional view of the subcooling section. The subcooling tubes are omitted in the figure. There are several subcooling baffles 6, which are distributed alternately along the axial direction of the subcooling tubes. On the one hand, they support the subcooling tubes, and on the other hand, they guide the condensate, so that the condensate flows across the subcooling tubes as much as possible, rather than flowing along the axial direction of the subcooling tubes. In addition, all the subcooling tubes in the subcooling section use the first flow of cooling water, so the liquid can obtain a greater degree of subcooling in the subcooling section.

[0030] In this example, the thickness of the plates for the equalization plate 2, guide plate 3, and skimming plate 4 is 6mm. The spacing of the heat exchange tube support plates 8 is usually around 600mm to 1000mm. Therefore, the equalization plate 2, guide plate 3, and skimming plate 4 are divided into many small plates. Each small plate is welded to the support plate 8 on the side, which eliminates the need for the previous support angle steel. The span of each small plate is not large, and the plate thickness is not thin. Each plate, together with the heat exchange tube support plate 8 and the tube sheet 13, forms a co-support structure, so the overall strength is very high and it will not deform. The upper side of each plate has a space of more than 6mm for the nearest heat exchange tube, which will not affect the production of tube installation and other operations.

[0031] The distance between the upper wall of the guide plate 3 and the skimming plate 4 and the wall of the heat exchange tube is 9mm, and the plate thickness is 6mm. Several plates are arranged in the axial and parallel directions, resulting in a large total liquid flow area and virtually preventing the liquid refrigerant from flooding the lower heat exchange tubes.

[0032] Figure 2 The cross-sectional view facing the intake pipe 11 and the air distribution plate 2 shows that the air distribution plate 2 is disposed between the tube sheets 13 and above the heat exchange tube support plates 8, specifically above the first support plate 801, the second support plate 802, the third support plate 803, and the fourth support plate 804. Using the heat exchange tube support plate 8 as a dividing element, the air distribution plate 2 is divided into several small sections: the first air distribution plate 201, the second air distribution plate 202, the third air distribution plate 203, the fourth air distribution plate 204, and the fifth air distribution plate 205. Each air distribution plate 2 has an air distribution opening, and the opening area near the intake pipe 1 is larger than that of the opening further away. The opening area of ​​the intake pipe 1 and the total area of ​​the gas equalization openings on each plate are relatively large. The exhaust flow velocity at the intake port section is about 15 m / s. The total area of ​​the gas equalization openings is much larger than the cross-section of the intake pipe 1, and the flow velocity will drop significantly, to the point that it is far below the minimum velocity specified in GB151 (about 6 m / s). This design controls the size of the gas equalization openings and the distance between the gas equalization plate 2 and the guide plate 3 that constitute the cooling zone. The overall adjustment space is relatively large, which makes it easy to adjust and increase the flow velocity of the gas in the cooling zone, improve the heat exchange efficiency, and at the same time avoid the fluid-induced vibration zone of the heat exchange tube, thus avoiding the vibration of the heat exchange tube.

[0033] This variable flow-channel shell-and-tube condenser effectively solves the problems of uneven gas distribution, condensate accumulation leading to decreased heat exchange efficiency, and low tube space utilization inherent in traditional shell-and-tube condensers through its unique structural design. The inclined guide plate 3, gas equalization plate 2, and skimming plate 4, along with the specially designed gas equalization opening and drain hole, ensure more rational flow of gas and condensate, improving the heat exchange efficiency of each heat exchange section. Simultaneously, the inclined arrangement of the heat exchange tubes and the optimized design of the subcooling section further enhance the overall performance of the condenser, providing a strong guarantee for the efficient operation of refrigeration or heat pump systems.

[0034] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A variable flow channel shell-and-tube condenser for improved efficiency, comprising a shell body, an inlet pipe and an outlet pipe disposed on the shell body, and heat exchange tubes, a gas distribution plate, a flow guide plate and several skimming plates disposed in the shell body via a tube sheet; Its features are, The guide plate is inclinedly disposed in the upper part of the cylinder. The end of the guide plate connected to the cylinder is a closed connection, and the connection end is lower than the free end of the guide plate. A gap is provided between the free end and the inner wall of the cylinder to allow gas to pass through. The air distribution plate is inclined above the guide plate, and the lower end of the guide plate is provided with an air distribution opening; Several skimming plates are spaced apart and inclined below the guide plate, and the lower end of each skimming plate is provided with a channel for liquid to drip; the higher end of each skimming plate is provided with a spacing for gas to pass through. The space between the guide plate and the gas distribution plate is a cooling zone, which is mainly used to displace and discharge the sensible heat of the superheated gas entering through the intake pipe. The area below the baffle plate is a condensation zone, which is mainly used to displace the latent heat of the gas cooled from the cooling zone and condense the gas into a liquid.

2. The variable flow channel shell-and-tube condenser according to claim 1, characterized in that, The tube sheet at one end of the cylinder has a water chamber section on the outside, and the tube sheet at the other end has a baffle section. The water chamber section is equipped with a water chamber baffle plate, which is used to isolate the inlet water and the outlet water. It cooperates with the tube sheet to form an inlet water chamber and a return water chamber. Half of the heat exchange tubes are connected to the inlet water chamber, and the other half are connected to the return water chamber. The water chamber baffle plate is inclined. The heat exchange tubes connected to the inlet water chamber are closer to the channel for liquid dripping than the heat exchange tubes connected to the return water chamber. The heat exchange tubes connected to the return water chamber are closer to the spacing for gas to pass through than the heat exchange tubes connected to the inlet water chamber.

3. The variable flow channel shell-and-tube condenser according to claim 2, characterized in that, The guide plate is provided with a drain hole at the connection end.

4. The variable flow channel shell-and-tube condenser according to any one of claims 1-3, characterized in that, The minimum distance between the skimming plate and the heat exchange tube above it is greater than 6 mm; the minimum distance between the guide plate and the heat exchange tube above it is greater than 6 mm.

5. The variable flow channel shell-and-tube condenser according to any one of claims 1-3, characterized in that, The gas equalization plate is parallel to the guide plate, and the skimming plate is parallel to the guide plate.

6. The variable flow channel shell-and-tube condenser according to claim 5, characterized in that, It also includes a supercooled cover plate, a supercooled pipe is provided below the supercooled cover plate, a channel for liquid to pass through is provided on the supercooled cover plate, and the supercooled pipe is connected to the water inlet chamber; the space below the supercooled cover plate is a supercooled section, which is used to cool the condensed liquid to a supercooled state, and the liquid outlet pipe is located below the supercooled pipe.

7. The variable flow channel shell-and-tube condenser according to any one of claims 1-3, characterized in that, The heat exchange tubes are inclined in the axial direction.

8. The variable flow channel shell-and-tube condenser according to any one of claims 1-3, characterized in that, The total area of ​​the air distribution openings on the air distribution plate is greater than the cross-sectional area of ​​the air intake pipe, and the area of ​​the openings closer to the air intake pipe is greater than the area of ​​the openings farther away from the air intake pipe.

9. The variable flow channel shell-and-tube condenser according to any one of claims 1-3, characterized in that, The gas equalization opening is elongated.

Images