Closed drying unit

Abstract

The utility model relates to a closed drying unit which comprises a shell, an evaporation cavity and a condensation cavity are separated in the shell through a partition plate, an air return opening is formed in the shell of the evaporation cavity, an air supply opening is formed in the shell of the condensation cavity, a dehumidification evaporator is installed in the evaporation cavity, a condenser is installed in the condensation cavity, and a heat pipe heat exchanger is installed in the shell. The heat pipe heat exchanger comprises an evaporation section and a condensation section, the evaporation section is arranged in the evaporation cavity and located on the air inlet side of the dehumidification evaporator, the condensation section is arranged in the condensation cavity and located on the air inlet side of the condenser, a first air opening is formed in the air exhaust side of the dehumidification evaporator, and a fan is installed on an air flowing path. The heat exchanger has the characteristics of high efficiency, energy conservation, small air flow resistance, small heat loss, simple structure, small volume and the like, not only can ensure the heat exchange efficiency, but also is favorable for reducing the volume of a unit.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of drying equipment technology, especially to a closed drying unit. BACKGROUND

[0002] At present, the closed high-temperature drying unit uses a total heat exchanger to recover heat and exchange total heat. The total heat exchanger is in the shape of a cuboid, and the return air and the air after evaporation flow through the heat exchanger in a perpendicular manner. The return air with a certain humidity and a relatively high temperature passes through the total heat exchanger to reach the dehumidification evaporator, where the temperature is lowered and the humidity is removed. The air after evaporation with a relatively low temperature and a small amount of humidity passes through the total heat exchanger in the other direction. The two kinds of air exchange heat in the total heat exchanger to achieve the purpose of total heat exchange.

[0003] However, the method of using the total heat exchanger to recover heat has the problems of large air resistance, low heat exchange efficiency, and complex structure. In addition, due to the structural characteristics of the total heat exchanger, a condensing fan and an evaporating fan also need to be configured. SUMMARY

[0004] The utility model mainly solves the technical problem of providing a closed drying unit with small air flow resistance, small heat loss, high heat exchange efficiency, simple structure, and small volume.

[0005] To solve the above technical problems, the basic idea of the technical solution of the utility model is as follows:

[0006] A closed drying unit, comprising a shell, an evaporation cavity and a condensation cavity are separated by a partition plate in the shell, a return air inlet is formed on the shell of the evaporation cavity, an air supply inlet is formed on the shell of the condensation cavity, a dehumidification evaporator is installed in the evaporation cavity, a condenser is installed in the condensation cavity, a heat pipe heat exchanger is installed in the shell, the heat pipe heat exchanger comprises an evaporation section and a condensation section, the evaporation section is located in the evaporation cavity and on the air inlet side of the dehumidification evaporator, the condensation section is located in the condensation cavity and on the air inlet side of the condenser, a first air inlet is arranged on the air outlet side of the dehumidification evaporator, an air flow path is formed between the return air inlet, the evaporation section of the heat pipe heat exchanger, the dehumidification evaporator, the first air inlet, the condensation section of the heat pipe heat exchanger, the condenser, and the air supply inlet, and a fan is installed on the air flow path.

[0007] Further, the evaporation section and the condensation section of the heat pipe heat exchanger are arranged vertically, the condensation section is located above the evaporation section, the refrigerant liquid in the condensation section flows downward to the evaporation section by gravity, and the condensation cavity is located above the evaporation cavity.

[0008] Further, the heat pipe heat exchanger is a flat plate heat exchanger and is installed obliquely in the shell, and the four edges of the heat pipe heat exchanger are connected with the shell.

[0009] Further, the included angle between the heat pipe heat exchanger and the bottom plate of the shell is 50-80°.

[0010] Further, the included angle between the heat pipe heat exchanger and the bottom plate of the shell is 50-80°.

[0011] Further, the dehumidification evaporator is vertically installed on the bottom plate of the shell, and the top of the dehumidification evaporator is connected with the heat pipe heat exchanger or the partition plate.

[0012] Or, the dehumidification evaporator is obliquely installed in the shell, the oblique direction of the dehumidification evaporator is the same as that of the heat pipe heat exchanger, and the top of the dehumidification evaporator is connected with the partition plate.

[0013] Further, the condenser is obliquely installed in the shell, the oblique direction of the condenser is the same as that of the heat pipe heat exchanger, and the top and bottom of the condenser are fixedly connected with the top plate and the partition plate of the shell.

[0014] Or, the condenser is vertically installed in the shell, and the top and bottom of the condenser are fixedly connected with the top plate and the partition plate of the shell.

[0015] Further, the return air inlet and the supply air outlet are arranged on the same side plate of the shell, and the supply air outlet is arranged above the return air inlet.

[0016] Further, the fan is installed at the supply air outlet.

[0017] Further, a second air inlet is arranged on the partition plate, the second air inlet is arranged on the air inlet side of the evaporation section of the heat pipe heat exchanger and between the condensation section of the heat pipe heat exchanger and the condenser, a wind valve is installed at the second air inlet, and the wind valve is used for adjusting the air volume of the air entering the condensation cavity through the second air inlet from the return air inlet.

[0018] Compared with the prior art, the closed dryer unit has the following advantages:

[0019] (1) The heat pipe heat exchanger is installed in the unit to replace the commonly used total heat exchanger to realize heat exchange between high-temperature and high-humidity air and low-temperature and low-humidity air, has the characteristics of high efficiency and energy saving, realizes efficient heat recovery by using the unique heat pipe technology, saves energy cost, and the heat pipe heat exchanger also has the characteristics of small air flow resistance, small heat loss, high heat exchange efficiency, simple structure, small size and the like, which not only can ensure the heat exchange efficiency, but also is conducive to reducing the space occupied by the heat exchanger and reducing the volume of the unit.

[0020] (2) The return air of the drying room passes through two times of dehumidification and heat absorption in sequence, solves the problem of high humidity and high heat recovery, improves the dehumidification effect of the drying system, improves the supply air temperature, greatly reduces the system energy consumption, and meets the requirements of the drying room on humidity and temperature.

[0021] (3) The utility model discloses a fan is installed in the unit only, can realize air field heat exchange, simplifies the unit structure, reduces the unit cost.

[0022] (4) The utility model discloses that the second air port is set up on the baffle between the condenser and the condensing section of heat pipe heat exchanger, utilizes the second air port to control part of return air not to carry out heat exchange with heat pipe heat exchanger, but directly enters the condensing cavity from the second air port, mixes with the air after the heat exchange of heat pipe heat exchanger condensing section, and then carries out heat exchange with the high-temperature refrigerant in the condenser, and then it is favorable to greatly improve the supply air temperature after heat absorption, meets the higher demand of the drying room to the temperature of drying air.

[0023] The specific embodiments of the utility model will be described in further detail below with reference to the drawings. DRAWINGS

[0024] The drawings are part of the utility model and are used to provide further understanding of the utility model, and the illustrative embodiments of the utility model and the description thereof are used to explain the utility model, but do not constitute improper limitation on the utility model. Obviously, the drawings in the following description are only some embodiments, and other drawings can be obtained by those skilled in the art without creative labor.

[0025] In the drawings:

[0026] Figure 1 It is the unit structure schematic diagram of the utility model.

[0027] In the drawings:

[0028] Shell 1, side plate 1a, bottom plate 1b, side plate 1c, top plate 1d, baffle 2, evaporation cavity 3, condensing cavity 4, return air port 5, supply air port 6, dehumidification evaporator 7, condenser 8, heat pipe heat exchanger 9, evaporation section 91, condensing section 92, first air port 10, fan 11, second air port 12.

[0029] It should be noted that the drawings and the written description are not intended to limit the scope of the concept of the utility model in any way, but to illustrate the concept of the utility model to those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical scheme and advantages of the embodiments of the utility model clearer, the technical scheme in the embodiments will be clearly and completely described below in combination with the drawings in the embodiments of the utility model, the following embodiments are used to illustrate the utility model, but not to limit the scope of the utility model.

[0031] In the description of the utility model, it needs to be explained that the orientation or position relation indicated by the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "inner", "outer" and the like is the orientation or position relation based on the orientation or position relation shown in the drawings, which is only for the convenience of describing the utility model and simplifying the description, and does not indicate or imply that the device or element indicated must have a particular orientation, be constructed and operated in a particular orientation, therefore, it cannot be understood as a limitation on the utility model.

[0032] In the description of the utility model, it needs to be explained that unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connection" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integrally connected, it can be mechanical connection, or electrical connection, it can be directly connected, or indirectly connected through intermediate medium.

[0033] As shown in Figure 1 The embodiment provides a closed dryer unit, which comprises a shell 1, an evaporation cavity 3 and a condensation cavity 4 are separated by a partition 2 in the shell 1, a return air inlet 5 is formed in the shell 1 of the evaporation cavity 3, a dehumidification evaporator 7 is installed in the evaporation cavity 3, a supply air inlet 6 is formed in the shell 1 of the condensation cavity 4, and a condenser 8 is installed in the condensation cavity 4. Wherein, the dehumidification evaporator 7 and the condenser 8 are preferably arranged along the thickness direction (i.e. Figure 1 The vertical direction of the paper) of the shell 1.

[0034] The shell 1 also has a compressor cavity (not shown in the figure), a compressor, a gas-liquid separator, a throttling element and the like are installed in the compressor cavity, the compressor, the condenser 8, the throttling element, the dehumidification evaporator 7 and the gas-liquid separator are sequentially connected through pipelines to form a refrigerant circulation loop. The working principle of the refrigerant circulation loop is that the compressor (not shown in the figure) compresses the low-temperature and low-pressure gaseous refrigerant into high-temperature and high-pressure superheated gas, enters the condenser 8, the refrigerant is condensed into liquid in the condenser 8, the liquid in the condenser 8 enters the dehumidification evaporator 7 after throttling and pressure reduction through the electronic expansion valve and the like (not shown in the figure), the refrigerant absorbs heat and evaporates into low-pressure gas in the dehumidification evaporator 7, and is then sucked into the compressor to complete a cycle. The compressor works continuously to achieve the effect of continuous heating, and continuously provides high-temperature and dry air to the drying room to achieve the purpose of drying.

[0035] A water pan (not shown in the figure) is arranged below the dehumidifying evaporator 7. The condensed water on the surface of the dehumidifying evaporator 7 after absorbing heat is collected in the water pan, and the water pan is connected with a drain pipe. The condensed water is drained out of the unit along the drain pipe.

[0036] In this embodiment, a heat pipe heat exchanger 9 is also arranged in the shell 1. The heat pipe heat exchanger 9 comprises an evaporation section 91 and a condensation section 92. Different refrigerant is filled in the heat pipe heat exchanger 9 according to the need, and the refrigerant absorbs heat to evaporate into gaseous state in the lower evaporation section 91. The gaseous refrigerant moves to the condensation section 92 under the action of pressure difference. The gaseous refrigerant exchanges heat with the outside in the condensation section 92, and the gaseous refrigerant becomes liquid refrigerant by releasing heat. The liquid refrigerant flows to the evaporation section 91 along the heat pipe.

[0037] In this embodiment, the evaporation section 91 of the heat pipe heat exchanger 9 is arranged in the evaporation cavity 3 and at the air inlet side of the dehumidifying evaporator 7, and the condensation section 92 is arranged in the condensation cavity 4 and at the air inlet side of the condenser 8. In this way, the high-humidity return air entering the return air inlet 5 is first subjected to heat absorption in the evaporation section 91 of the heat pipe heat exchanger 9 before passing through the dehumidifying evaporator 7, so that the temperature of the return air is lowered and the relative humidity of the return air is increased. The return air is further subjected to secondary heat absorption in the dehumidifying evaporator 7 to evaporate completely into gaseous refrigerant, and most of the moisture contained in the return air is condensed into water and discharged, so that the purpose of dehumidification is achieved. The return air with lower temperature and less moisture continues to flow to the condensation section 92 of the heat pipe heat exchanger 9 to be subjected to primary heat absorption, so that the temperature of the return air is increased. Finally, the return air is subjected to secondary heat absorption in the condenser 8, and the high-temperature air after heating is sent to the drying room through the supply air outlet 6 to dry the articles in the room.

[0038] In this embodiment, preferably, the evaporation section 91 and the condensation section 92 of the heat pipe heat exchanger 9 are arranged in an up-down manner, and the condensation section 92 is arranged above the evaporation section 91. The gaseous refrigerant moves upward to the upper condensation section 92 under the action of pressure difference. The gaseous refrigerant exchanges heat with the outside in the upper condensation section 92, and the gaseous refrigerant becomes liquid refrigerant by releasing heat. The liquid refrigerant flows to the lower evaporation section 91 along the wall of the heat pipe under the action of gravity. In this embodiment, the condensation cavity 4 is arranged above the evaporation cavity 3 and is separated by the partition 2. Further preferably, the return air inlet 5 and the supply air outlet 6 are arranged on the same side plate 1a of the shell 1, and the supply air outlet 6 is arranged above the return air inlet 5. The heat pipe heat exchanger structure for realizing the circulation of refrigerant under the action of gravity is beneficial to simplifying the structure and reducing the occupied space of the heat pipe heat exchanger 9.

[0039] In this embodiment, the heat pipe heat exchanger 9 is further preferably a flat plate heat exchanger, and is arranged along the thickness direction of the shell 1. This is advantageous for increasing the heat exchange area, and also helps to reduce the space occupied by the heat pipe heat exchanger 9 in the shell 1. The four edges of the flat plate heat exchanger are connected to the inner walls of the shell 1. Specifically, the bottom edge of the heat pipe heat exchanger 9 is connected to the bottom plate 1b of the shell 1, the top edge of the heat pipe heat exchanger 9 is connected to the other side plate 1c opposite the side plate 1a of the shell 1, the top edge of the heat pipe heat exchanger 9 can also be connected to the top plate 1d of the shell 1, and the front and rear edges of the heat pipe heat exchanger 9 are connected to the front and rear plates (not shown in the figure) of the shell 1. In this way, it can be ensured that all the air that needs to be heat exchanged with the heat pipe heat exchanger 9 can pass through the heat pipe heat exchanger 9, and will not flow through the gaps around it, thereby affecting the heat exchange effect.

[0040] In this embodiment, it is further preferred that the heat pipe heat exchanger 9 is installed obliquely in the shell 1, which is advantageous for increasing the windward area of the heat pipe heat exchanger 9 and improving the heat exchange efficiency of the heat pipe heat exchanger 9. In this embodiment, it is further preferred that the angle a between the heat pipe heat exchanger 9 and the bottom plate of the shell 1 is 50-80°, and the optimal range is 60°-70°. In this way, the heat exchange effect can be achieved, while the air flow resistance is reduced, and the occupied space of the heat pipe heat exchanger 9 and the volume of the unit are also reduced.

[0041] In this embodiment, it is further preferred that the oblique direction of the heat pipe heat exchanger 9 is that the angle a between the heat pipe heat exchanger 9 and the bottom plate 1b of the shell 1 towards the evaporator 7 is an acute angle, that is, the heat pipe heat exchanger 9 is inclined from the bottom end upwards, from the direction close to the return air outlet 5 and the supply air outlet 6 to the direction away from the return air outlet 5 and the supply air outlet 6.

[0042] In this embodiment, the first air outlet 10 is provided on the partition plate 2, and the first air outlet 10 communicates the evaporation cavity 3 and the condensation cavity 4. The first air outlet 10 is arranged on the air outlet side of the dehumidification evaporator 7, so that the air flows into the condensation cavity 4 upwards through the first air outlet 10 after being heat exchanged by the dehumidification evaporator 7, and an air flow path is formed between the return air outlet 5, the evaporation section 91 of the heat pipe heat exchanger 9, the dehumidification evaporator 7, the first air outlet 10, the condensation section 92 of the heat pipe heat exchanger 9, the condenser 8, and the supply air outlet 6.

[0043] In this embodiment, it is further preferred that the partition plate 2 is arranged only on one side of the heat pipe heat exchanger 9 towards the return air outlet 5 and the supply air outlet 6 (i.e. the left side of the heat pipe heat exchanger 9), and is not arranged on the other side of the heat pipe heat exchanger 9 away from the return air outlet 5 and the supply air outlet 6 (i.e. the right side of the heat pipe heat exchanger 9). Figure 1 Figure 1 ​The right side of the heat pipe heat exchanger 9 is not provided with the partition plate 2. In this structure, the top of the dehumidification evaporator 7 is connected with the heat pipe heat exchanger 9 at the joint of the evaporating section 91 and the condensing section 92, and the dehumidification evaporator 7 is completely open above the air outlet side, which is taken as the first air outlet 10. In this way, the structure of the unit is simplified, and the flow resistance of the air flowing through the first air outlet 10 is reduced.

[0044] In this embodiment, another embodiment is provided, i.e. the heat pipe heat exchanger 9 is installed through the partition plate 2 on the side of the heat pipe heat exchanger 9 away from the air return outlet 5 and the air supply outlet 6, and the first air outlet 10 is formed in the partition plate 2 on the side of the heat pipe heat exchanger 9 away from the air return outlet 5 and the air supply outlet 6. Figure 1 The right side of the heat pipe heat exchanger 9 is provided with the partition plate 2, i.e. the heat pipe heat exchanger 9 is installed through the partition plate 2, and the first air outlet 10 is formed in the partition plate 2 on the side of the heat pipe heat exchanger 9 away from the air return outlet 5 and the air supply outlet 6. In this structure, the top of the dehumidification evaporator 7 can be connected with the heat pipe heat exchanger 9 or directly connected with the partition plate 2.

[0045] In this embodiment, the fan 11 is installed on the air flow path between the air return outlet 5 and the air supply outlet 6, and more preferably, the fan 11 is installed at the air supply outlet 6 and is an axial flow fan. Under the action of one fan 11, the air in the drying room enters the casing 1 through the air return outlet 5, and then sequentially passes through the evaporating section 91 of the heat pipe heat exchanger 9, the dehumidification evaporator 7, the first air outlet 10, the condensing section 92 of the heat pipe heat exchanger 9 and the condenser 8, and finally is sent to the drying room through the air supply outlet 6. The static pressure of the fan 11 is equal to the resistance of the evaporating section 91 of the heat pipe heat exchanger 9 + the resistance of the dehumidification evaporator 7 + the resistance of the condensing section 92 of the heat pipe heat exchanger 9 + the resistance of the condenser 8. In this way, the air in the unit can be circulated and flowed under the action of one fan 11, which greatly simplifies the structure of the unit and reduces the cost.

[0046] In this embodiment, the dehumidification evaporator 7 is further preferably vertically installed on the bottom plate 1b of the casing 1, and the top of the dehumidification evaporator 7 is connected with the heat pipe heat exchanger 9 (the joint between the evaporating section 91 and the condensing section 92). In this way, the heat exchange efficiency is ensured, the flow resistance of the air is reduced, the space occupied by the heat pipe heat exchanger 9 and the dehumidification evaporator 7 is reduced, and the overall volume of the unit is reduced.

[0047] For the mounting structure of the dehumidification evaporator 7, another embodiment is also provided in the embodiment, and the dehumidification evaporator 7 can also be installed in the housing 1 in a tilted manner. The tilt direction of the dehumidification evaporator 7 is the same as that of the heat pipe heat exchanger 9, and the tilt angle of the dehumidification evaporator 7 is also the same as that of the heat pipe heat exchanger 9. That is, the dehumidification evaporator 7 is arranged in parallel with the evaporation section 91 of the heat pipe heat exchanger 9, and there is a certain spacing between the dehumidification evaporator 7 and the evaporation section 91 of the heat pipe heat exchanger 9. In this structure, a partition plate 2 also needs to be arranged above the dehumidification evaporator 7, and the top and bottom of the dehumidification evaporator 7 are connected with the partition plate 2 and the bottom plate 1b of the housing 1 respectively.

[0048] In the embodiment, it is further preferred that the condenser 8 is also installed in the housing 1 in a tilted manner. The tilt direction of the condenser 8 is the same as that of the heat pipe heat exchanger 9, and the tilt angle of the condenser 8 is also the same as that of the heat pipe heat exchanger 9. That is, the condenser 8 is arranged in parallel with the condensation section 92 of the heat pipe heat exchanger 9, and there is a certain spacing between the condenser 8 and the condensation section 92 of the heat pipe heat exchanger 9. In this structure, the top and bottom of the condenser 8 are connected with the top plate 1d of the housing 1 and the partition plate 2 respectively.

[0049] For the mounting structure of the condenser 8, another embodiment is also provided in the embodiment, and the condenser 8 is installed in the housing 1 in a vertical manner. The condenser 8 is vertically installed between the top plate 1d of the housing 1 and the partition plate 2. In this structure, there is still a certain spacing between the condenser 8 and the condensation section 92 of the heat pipe heat exchanger 9.

[0050] In the embodiment, it is further preferred that the second air inlet 12 is formed in the partition plate 2. The second air inlet 12 is arranged on the partition plate 2 on the air inlet side of the evaporation section 91 of the heat pipe heat exchanger 9 and between the condensation section 92 of the heat pipe heat exchanger 9 and the condenser 8. The bypass air flow path is formed between the return air inlet 5 and the supply air inlet 6 by the second air inlet 12. Part of the air entering from the return air inlet 5 can directly enter the condensation cavity 4 through the second air inlet 12 without heat exchange with the heat pipe heat exchanger 9, but is mixed with the air after heat exchange with the condensation section 92 of the heat pipe heat exchanger 9, and then is heat exchanged with the high-temperature refrigerant in the condenser 8, thereby improving the air inlet temperature of the condenser 8, which is conducive to greatly improving the temperature of the heat-absorbed supply air, meeting the higher demand of the drying room for the temperature of the drying air, and even ensuring that the supply air temperature reaches more than 120°C.

[0051] An air valve (not shown in the figure) is installed at the second air inlet 12, which can be used to adjust the bypass air volume. In the embodiment, in order to simplify the control logic, it is further preferred that the air valve is calibrated with a set opening degree when it is shipped from the factory, which is used to control the bypass air volume directly introduced into the air inlet side of the condenser 8 to be a set value. As long as there is return air, a fixed proportion of air volume enters the air inlet side of the condenser 8 through the second air inlet 12.

[0052] In this embodiment, the closed dryer unit wind field flows as follows:

[0053] 1. Under the action of the fan 11, the high-temperature and high-humidity return air in the drying room enters the evaporation cavity 3 of the dryer unit shell 1 from the return air inlet 5.

[0054] 2. A small part of the return air enters the inlet side of the condenser 8 in the condensation cavity 4 through the second air inlet 12.

[0055] 3. Most of the return air passes through the evaporation section 91 of the heat pipe heat exchanger 9. The refrigerant in the heat pipe heat exchanger 9 absorbs the heat in the return air and evaporates into a gaseous state. The gaseous refrigerant moves upward into the condensation section 92. At this time, the high-temperature and high-humidity return air releases heat and its temperature drops after passing through the evaporation section 91. The relative humidity of the return air increases. Under the action of the fan 11, the return air continues to flow to the dehumidification evaporator 7. After passing through the dehumidification evaporator 7, the temperature of the return air further decreases, and most of the water contained in the return air condenses into water and flows out from the drain pipe.

[0056] 4. The return air with lower temperature and less moisture continues to flow upward through the first air inlet 10 into the condensation cavity 4 and further flows to the condensation section 92 of the heat pipe heat exchanger 9. The refrigerant in the heat pipe heat exchanger 9 condenses and releases heat. The condensed refrigerant liquid flows back to the evaporation section 91 along the heat pipe to continue to absorb heat. After the heat exchange between the return air and the refrigerant in the heat pipe heat exchanger 9, the heat is transferred to the return air. The initially heated return air mixes with the primary return air directly entering from the second air inlet 12 and reaches the condenser 8.

[0057] 5. The mixed air exchanges heat with the high-temperature refrigerant in the condenser 8. After being heated by the condenser 8, the temperature of the mixed air increases. Finally, under the action of the fan 11, the mixed air is sent out from the air supply inlet 6 to the drying room. Under the action of the fan 11, the cycle continues, which reduces the humidity and increases the temperature in the drying room, achieving the purpose of drying the articles.

[0058] After adopting the above scheme, the following beneficial effects are achieved:

[0059] 1. The heat pipe heat exchanger 9 is installed in the dryer unit to replace the commonly used total heat exchanger to achieve heat exchange between high-temperature and high-humidity air and low-temperature and low-humidity air, which has the characteristics of high efficiency and energy saving. The unique heat pipe technology realizes efficient heat recovery, saves energy costs, and the heat pipe heat exchanger also has the characteristics of small air flow resistance, small heat loss, high heat exchange efficiency, simple structure, small size, etc. It not only ensures the heat exchange efficiency, but also helps to reduce the space occupied by the heat exchanger and the volume of the unit.

[0060] 2. In this drying unit, the return air from the drying room undergoes two dehumidification processes and two heat absorption and heating processes. This solves the problem of high humidity and high heat recovery, improves the dehumidification effect of the drying system, and also increases the supply air temperature, greatly reducing system energy consumption and meeting the humidity and temperature requirements of the drying room.

[0061] 3. Only one fan 11 needs to be installed in the dryer unit to achieve airflow heat exchange, which simplifies the unit structure and reduces the unit cost.

[0062] 4. In this drying unit, a second air vent 12 is opened on the partition 2 between the condenser 8 and the condensing section 92 of the heat pipe heat exchanger 9. The second air vent 12 forms a bypass airflow path between the return air vent 5 and the supply air vent 6. Part of the air entering from the return air vent 5 can directly enter the condensing chamber 4 through the second air vent 12. Instead of exchanging heat with the heat pipe heat exchanger 9, it mixes with the air that has exchanged heat through the condensing section 92 of the heat pipe heat exchanger 9, and then exchanges heat with the high-temperature refrigerant in the condenser 8. This increases the inlet air temperature of the condenser 8, which is beneficial to significantly increase the supply air temperature after heat absorption, meeting the higher temperature requirements of the drying room for drying air, and can even ensure that the supply air temperature reaches above 120℃.

[0063] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model in any way. Although the present utility model has been disclosed above with reference to a preferred embodiment, it is not intended to limit the present utility model. Any person skilled in the art can make some modifications or alterations to the above-described technical content to create equivalent embodiments without departing from the scope of the present utility model. The implementation schemes in the above embodiments can be further combined or replaced. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present utility model without departing from the scope of the present utility model shall still fall within the scope of the present utility model.

Claims

1. A closed dryer train comprising a housing, characterized in that: The shell is provided with a partition plate to divide an evaporation cavity and a condensation cavity, an air return opening is formed on the shell of the evaporation cavity, an air supply opening is formed on the shell of the condensation cavity, a dehumidification evaporator is installed in the evaporation cavity, a condenser is installed in the condensation cavity, and a heat pipe heat exchanger is installed in the shell, the heat pipe heat exchanger comprises an evaporation section and a condensation section, the evaporation section is arranged in the evaporation cavity and on the air inlet side of the dehumidification evaporator, the condensation section is arranged in the condensation cavity and on the air inlet side of the condenser, a first air opening is arranged on the air outlet side of the dehumidification evaporator, an air flow path is formed between the air return opening, the evaporation section of the heat pipe heat exchanger, the dehumidification evaporator, the first air opening, the condensation section of the heat pipe heat exchanger, the condenser and the air supply opening, and a fan is installed on the air flow path.

2. The closed dryer group according to claim 1, characterized in that: The evaporation section and the condensation section of the heat pipe heat exchanger are arranged in an up-down manner, the condensation section is arranged above the evaporation section, and the refrigerant liquid in the condensation section flows downward to the evaporation section by gravity.

3. The closed dryer group according to claim 2, characterized in that: The heat pipe heat exchanger is a flat plate heat exchanger and is arranged in the shell in an inclined manner, and four edges of the heat pipe heat exchanger are connected with the shell respectively.

4. The closed dryer group according to claim 3, characterized in that: The included angle between the heat pipe heat exchanger and the bottom plate of the shell is 50-80°.

5. The closed dryer group according to claim 3, characterized in that: The included angle between the heat pipe heat exchanger and the bottom plate of the shell towards the dehumidification evaporator is an acute angle.

6. The closed dryer group according to claim 3, characterized in that: The dehumidification evaporator is vertically arranged on the bottom plate of the shell, and the top of the dehumidification evaporator is connected with the heat pipe heat exchanger or the partition plate. Alternatively, the dehumidification evaporator is arranged in the shell in an inclined manner, the inclination direction of the dehumidification evaporator is the same as that of the heat pipe heat exchanger, and the top of the dehumidification evaporator is connected with the partition plate.

7. The closed dryer group according to claim 3, characterized in that: The condenser is arranged in the shell in an inclined manner, the inclination direction of the condenser is the same as that of the heat pipe heat exchanger, and the top and bottom of the condenser are fixedly connected with the top plate and the partition plate of the shell respectively. Alternatively, the condenser is vertically arranged in the shell, and the top and bottom of the condenser are fixedly connected with the top plate and the partition plate of the shell respectively.

8. The closed dryer group according to claim 2, characterized in that: The air return opening and the air supply opening are arranged on the same side plate of the shell, and the air supply opening is arranged above the air return opening.

9. The closed dryer group according to claim 1, characterized in that: The fan is arranged at the air supply opening.

10. The closed dryer group according to any one of claims 1-9, characterized in that: A second air opening is further formed on the partition plate, the second air opening is arranged on the air inlet side of the evaporation section of the heat pipe heat exchanger and between the condensation section of the heat pipe heat exchanger and the condenser, a damper is arranged at the second air opening, and the damper is used to adjust the air volume of the air entering the condensation cavity directly through the second air opening from the air return opening.

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