Composite heat exchanger for freezing dryer

Abstract

The utility model discloses a compound heat exchanger for a refrigeration dryer, which comprises an upright cavity, a precooling module and an evaporation module which are stacked up and down are arranged in the upright cavity, and the precooling module is positioned above the evaporation module; a compressed air inlet channel which vertically penetrates through the pre-cooling module and the evaporation module is arranged between the pre-cooling module and the evaporation module and is communicated with a compressed air inlet; a compressed air outlet channel is further arranged in the pre-cooling module and is communicated with the compressed air outlet; a refrigerant channel is further arranged in the evaporation module. A water vapor separation module is arranged at the bottom of the vertical cavity, and a backflow channel is further arranged on the inner side of the vertical cavity. The pre-cooling module and the evaporation module share a cavity and are integrated, redundant bending of a traditional sectional type flow channel is reduced, the distance of a channel where compressed air flows through is shortened, and pressure loss when the compressed air passes through the refrigeration dryer is reduced.

Description

Technical Field

[0001] This utility model belongs to the field of refrigerated air dryer technology, and specifically relates to a composite heat exchanger for refrigerated air dryers. Background Technology

[0002] Refrigerated air dryers are widely used for drying compressed air. Figure 3 This is a basic flow chart of a refrigerated air dryer, which includes five parts: the refrigeration compressor drives the refrigerant into the condenser, the refrigerant is cooled and becomes a low-temperature liquid refrigerant after passing through the expansion valve, and then enters the evaporator. The heat source of the evaporator is compressed air. After the refrigerant absorbs heat and is vaporized in the evaporator, it enters the refrigeration compressor again, forming a cycle.

[0003] After passing through the evaporator, the compressed air is cooled and liquid water is released, achieving a drying effect. The dried compressed air (usually at a temperature of 8-15°C) enters the precooler, where it exchanges heat with the compressed air that needs to be dried (usually at a temperature of 40-55°C). This reduces the temperature of the compressed air before it enters the evaporator, thereby reducing the amount of heat exchange in the evaporator and achieving the goal of reducing the power of the refrigeration compressor.

[0004] However, in practical applications, evaporators and precoolers are often separate and horizontally arranged, with simple structures, which cannot achieve effective drying of compressed air, especially in summer. Usually, the dew point of the dried compressed air exceeds 10°C, and the compressed air is compressed to 0.3 to 0.4 Bar after passing through the refrigerated dryer. Utility Model Content

[0005] To address the aforementioned problems, this invention provides a composite heat exchanger for refrigerated air dryers, which can shorten the channel distance through which compressed air flows, reduce the pressure loss of compressed air when passing through the refrigerated air dryer, and improve the drying effect.

[0006] Therefore, the technical solution of this utility model is: a composite heat exchanger for a refrigerated dryer, comprising a vertical cavity, wherein a compressed air inlet and a compressed air outlet are provided at the top of the vertical cavity, and a refrigerant inlet and a refrigerant outlet are provided on the side;

[0007] The upright cavity is equipped with a precooling module and an evaporation module stacked vertically, with the precooling module located above the evaporation module;

[0008] A vertically penetrating compressed air intake channel is provided between the precooling module and the evaporation module, and is connected to the compressed air inlet;

[0009] The precooling module is also equipped with a compressed air outlet channel, which is connected to the compressed air outlet.

[0010] The evaporation module is also provided with a refrigerant channel, which connects the refrigerant inlet and the refrigerant outlet;

[0011] The bottom of the vertical cavity is equipped with a water vapor separation module, and the inner side of the vertical cavity is also equipped with a return channel. The bottom of the compressed air inlet channel is connected to the compressed air outlet channel via the water vapor separation module and the return channel.

[0012] Based on the above scheme and as a preferred embodiment of the above scheme: the gas flow direction in the compressed air inlet channel is opposite to the gas flow direction in the compressed air outlet channel, and the compressed air inlet is higher than the compressed air outlet.

[0013] Based on the above scheme and as a preferred embodiment of the above scheme: the refrigerant inlet is lower than the refrigerant outlet, and the refrigerant flow direction in the refrigerant channel is opposite to the gas flow direction in the compressed air intake channel.

[0014] Based on the above scheme and as a preferred embodiment of the above scheme: the bottom of the upright cavity is a conical structure, the water vapor separation module is placed at the bottom of the conical structure, and the water vapor separation module is in the shape of a honeycomb filter; the bottom of the upright cavity is also provided with a drain outlet, and a drain valve is provided at the drain outlet.

[0015] Based on the above scheme and as a preferred embodiment of the above scheme: the precooling module is provided with a number of first aluminum fins, the compressed air intake channel passes between adjacent first aluminum fins, and a compressed air outlet channel is formed between adjacent first aluminum fins.

[0016] Based on the above scheme and as a preferred embodiment of the above scheme: the evaporation module is provided with a second aluminum fin, the compressed air intake channel passes between adjacent second aluminum fins, and a refrigerant channel is formed between adjacent second aluminum fins.

[0017] Based on the above scheme and as a preferred embodiment of the above scheme: the outer side of the upright cavity is fitted with a heat-insulating outer cover.

[0018] Compared with the prior art, the beneficial effects of this utility model are:

[0019] 1. The pre-cooling module and evaporation module are integrated into a common cavity design, which reduces the redundant bends of the traditional segmented flow channel, shortens the channel distance through which the compressed air flows, and reduces the pressure loss of the compressed air when passing through the refrigerated dryer.

[0020] 2. The precooling module and evaporation module adopt a vertical structure, which allows the undried compressed air to exchange heat with the dried compressed air and refrigerant from top to bottom in sequence, while the condensate produced during the cooling process can be quickly collected and made full use of the water's own gravity to flow out.

[0021] 3. A water vapor separation module is installed at the bottom of the upright cavity. The micropores of the honeycomb filter intercept and coalesce to capture small water droplets, which then coalesce into larger droplets and fall off. This facilitates the separation of particulate liquid water and improves the drying effect. Furthermore, the bottom of the upright cavity has a conical structure, which is conducive to the further collection of liquid water.

[0022] 4. Both the precooling module and the evaporation module adopt an increased aluminum fin structure, which increases the heat exchange area and improves the heat exchange effect. The precooling module allows the output lower-temperature compressed air and the input higher-temperature compressed air to fully exchange heat, making full use of the cold source, reducing the load on the refrigeration compressor, and making the entire refrigerated dryer more energy efficient. The dew point temperature of the compressed air after drying by this design can be stabilized at 3-5℃.

[0023] 5. An insulating cover is installed on the outside of the vertical cavity to keep it warm and avoid the radiative loss of heat / cold energy during the heat exchange process. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the structure of this utility model;

[0025] Figure 2 This is a flowchart illustrating the workflow of this utility model.

[0026] Figure 3 This is a basic flowchart of an existing refrigerated dryer.

[0027] The diagram is labeled as follows: Compressed air inlet 1, Compressed air outlet 2, Refrigerant inlet 3, Refrigerant outlet 4, Precooling module 5, Evaporation module 6, Water vapor separation module 7, Drain valve 8, Vertical cavity 9, Insulation cover 10, Compressed air inlet channel 11, Compressed air outlet channel 12, Refrigerant channel 13, Return channel 14, Expansion valve 15, Compressor 16. Detailed Implementation

[0028] In the description of this utility model, it should be noted that the directional terms such as "center", "horizontal (X)", "longitudinal (Y)", "vertical (Z)", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", and "counterclockwise" indicate the orientation and positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. They should not be construed as limiting the specific protection scope of this utility model.

[0029] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features. Thus, the use of "first" and "second" to define a feature may explicitly or implicitly include one or more of that feature. In the description of this utility model, "several" or "a number" means two or more, unless otherwise explicitly specified.

[0030] See the attached figures. The composite heat exchanger for the refrigerated dryer described in this embodiment includes a vertical cavity 9, and an insulation cover 10 is fitted on the outside of the vertical cavity 9 to avoid radiative loss of heat / cold energy during the heat exchange process.

[0031] The top of the vertical cavity 9 is provided with a compressed air inlet 1 and a compressed air outlet 2, and the compressed air inlet 1 is higher than the compressed air outlet 2. The compressed air inlet 1 is connected by a flange, and the temperature range of the compressed air here is usually 40 to 55°C. The compressed air outlet 2 is connected by a flange, and the temperature of the compressed air output here after passing through the heat exchanger is usually 5 to 8°C lower than the temperature of the compressed air inlet.

[0032] The upright cavity 9 has a refrigerant inlet 3 and a refrigerant outlet 4 on its middle side, and the refrigerant inlet 3 is lower than the refrigerant outlet 4. The refrigerant inlet 3 is connected to the expansion valve of the refrigerated dryer, and the refrigerant temperature here is usually 3-5℃; the refrigerant outlet 4 is connected to the refrigeration compressor.

[0033] The upright cavity 9 is provided with a precooling module 5 and an evaporation module 6 stacked vertically, with the precooling module 5 located above the evaporation module 6; a vertically penetrating compressed air intake channel 11 is provided between the precooling module 5 and the evaporation module 6, and is connected to the compressed air inlet 1; the undried, high-temperature compressed air input into the compressed air inlet 1 passes through the precooling module 5 and the evaporation module 6 sequentially from top to bottom through the compressed air intake channel 11, and heat exchange occurs.

[0034] The precooling module 5 is provided with several first aluminum fins. The compressed air inlet channel 11 passes between adjacent first aluminum fins, and a compressed air outlet channel 12 is also formed between adjacent first aluminum fins and is connected to the compressed air outlet 2. The compressed air outlet channel 12 is filled with freeze-dried compressed air, and the flow direction is from bottom to top, and it exchanges heat with the undried, higher-temperature compressed air in the compressed air inlet channel 11 in a countercurrent manner.

[0035] Meanwhile, the evaporation module 6 is equipped with second aluminum fins. The compressed air inlet channel 11 extends downward into the evaporation module 6 and passes between adjacent second aluminum fins, forming a refrigerant channel 13 between them. The refrigerant inlet 3 and refrigerant outlet 4 are located on the side of the evaporation module 6 and are connected to the refrigerant channel 13 within the evaporation module. The refrigerant in the refrigerant channel 13 flows from bottom to top, engaging in counter-current heat exchange with the compressed air flowing in the compressed air inlet channel 11, which has been cooled by the precooler. The compressed air is cooled here and precipitates liquid water, achieving the purpose of drying.

[0036] The bottom of the upright cavity 9 is a conical structure, and the water vapor separation module 7 is placed at the bottom of the cone. The water vapor separation module 7 is in the shape of a honeycomb filter. When compressed air passes through, it will adhere to and collect liquid water. The bottom of the upright cavity 9 is also provided with a drain outlet, and a drain valve 8 is provided at the drain outlet, which can be used to drain the condensate in time.

[0037] The inner side of the upright cavity 9 is also provided with a return channel 14. After being cooled in the compressed air inlet channel 11, the compressed air is dried by the water vapor separation module and then enters the return channel 14. It then flows through the return channel 14 to the compressed air outlet channel 12 and finally flows out from the compressed air outlet 2.

[0038] During operation, compressed air enters the pre-cooling module 5 of the vertical cavity 9 from the compressed air inlet 1, causing the high-temperature, undried compressed air and the freeze-dried compressed air to exchange heat in a counter-current manner. The compressed air, cooled by the pre-cooler, continues to enter the evaporation module for further heat exchange with the refrigerant. Here, the compressed air is cooled and liquid water is precipitated, achieving the purpose of drying. Then, the compressed air flows through the water vapor separation module 7, where the liquid water in the compressed air adheres to the honeycomb filter screen. The compressed air then flows back to the compressed air outlet channel 12 of the pre-cooling module through the return channel 14 and is finally discharged from the compressed air outlet 2.

[0039] The refrigerant from the expansion valve 15 (the refrigerant here is usually 3 to 5°C) enters the refrigerant channel 13 of the evaporation module 6 through the refrigerant inlet 3, and then connects to the refrigeration compressor 16 through the refrigerant outlet 4.

[0040] The above description is merely a preferred embodiment of this utility model. The protection scope of this utility model is not limited to the above embodiments. All technical solutions falling within the scope of this utility model's concept are protected. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principle of this utility model should also be considered within the protection scope of this utility model.

Claims

1. A composite heat exchanger for a refrigerated dryer, characterized in that: It includes a vertical cavity, wherein the top of the vertical cavity is provided with a compressed air inlet and a compressed air outlet, and the side is provided with a refrigerant inlet and a refrigerant outlet; The upright cavity is equipped with a precooling module and an evaporation module stacked vertically, with the precooling module located above the evaporation module; A vertically penetrating compressed air intake channel is provided between the precooling module and the evaporation module, and is connected to the compressed air inlet; The precooling module is also equipped with a compressed air outlet channel, which is connected to the compressed air outlet. The evaporation module is also provided with a refrigerant channel, which connects the refrigerant inlet and the refrigerant outlet; The bottom of the vertical cavity is equipped with a water vapor separation module, and the inner side of the vertical cavity is also equipped with a return channel. The bottom of the compressed air inlet channel is connected to the compressed air outlet channel via the water vapor separation module and the return channel.

2. The composite heat exchanger for a refrigerated dryer as described in claim 1, characterized in that: The gas flow direction in the compressed air intake channel is opposite to that in the compressed air outlet channel, and the compressed air inlet is higher than the compressed air outlet.

3. The composite heat exchanger for a refrigerated dryer as described in claim 2, characterized in that: The refrigerant inlet is lower than the refrigerant outlet, and the refrigerant flow direction in the refrigerant channel is opposite to the gas flow direction in the compressed air intake channel.

4. The composite heat exchanger for a refrigerated dryer as described in claim 1, characterized in that: The bottom of the upright cavity is a conical structure, and the water vapor separation module is placed at the bottom of the conical structure. The water vapor separation module is in the shape of a honeycomb filter. The bottom of the upright cavity is also provided with a drain outlet, and a drain valve is provided at the drain outlet.

5. A composite heat exchanger for a refrigerated dryer as described in claim 1, characterized in that: The precooling module is provided with a number of first aluminum fins, and the compressed air intake channel passes between adjacent first aluminum fins, and a compressed air outlet channel is formed between adjacent first aluminum fins.

6. A composite heat exchanger for a refrigerated dryer as described in claim 1, characterized in that: The evaporation module is equipped with a second aluminum fin, and the compressed air intake channel passes between adjacent second aluminum fins, forming a refrigerant channel between adjacent second aluminum fins.

7. A composite heat exchanger for a refrigerated dryer as described in claim 1, characterized in that: The upright cavity is fitted with an insulated outer cover.

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